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Subject: Embedded Processor and Microcontroller primer and FAQ

This article was archived around: 12 Sep 1997 10:51:14 GMT

All FAQs in Directory: microcontroller-faq
All FAQs posted in: comp.arch.embedded, comp.robotics.misc, comp.realtime, sci.electronics.design, alt.comp.hardware.homebuilt
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Archive-name: microcontroller-faq/primer Posting-Frequency: monthly Last-modified: September 11, 1997
This article is a primer and general FAQ about embedded processors and microcontrollers. Included is a collection of information sources. The following topics are addressed: 0) Rantings and ravings (to make the FAQ zero-based) 1) ABOUT THIS FAQ 1.1) Who put this FAQ together? 1.2) How can I contribute to this FAQ? 1.3) What newsgroups will this FAQ be posted to? 1.4) May I distribute this FAQ or post it somewhere else? 2) MICROCONTROLLERS 2.1) What is a Microcontroller? 2.2) Applications 2.3) Flavors 3) THE MICROCONTROLLER MARKET 3.1) Shipments 3.2) Industrial applications 3.3) Deciding whose microcontroller to use 3.4) The players 4) MICROCONTROLLER FEATURES 4.1) Fabrication techniques 4.2) Architectural features 4.3) Advanced Memory options 4.4) Power Management and Low Voltage 4.5) I/O 4.6) Interrupts 4.7) Special microcontroller features 5) SOME POPULAR MICROCONTROLLERS 6) GETTING STARTED WITH MICROCONTROLLERS 6.1) Evaluation Kits/Boards 6.2) Easy chips to use 6.3) Software (cheap and easy) 7) MICROCONTROLLER PROGRAMMING LANGUAGES 7.1) Machine/Assembly language 7.2) Interpreters 7.3) Compilers 7.4) Fuzzy Logic and Neural Networks 8) DEVELOPMENT TOOLS 8.1) Simulators 8.2) Resident Debuggers 8.3) Emulators 8.4) Good Stereo System 9) FINDING OUT MORE ABOUT MICROCONTROLLERS 9.1) Books 9.2) Data and Reference Books 9.3) Periodicals 9.4) USENET newsgroups 9.5) Internet sources of information on specific microcontrollers 10) MICROCONTROLLER FREE SOFTWARE SOURCES 10.1) FTP sites 10.2) WEB pages 10.2) BBSs 10.3) Mailing lists 11) SOURCES FOR PARTS 0) Rantings and ravings Disclaimer: Just so it is understood, the "rantings and ravings" are my rantings and ravings. My readers are refined and sophisticated and would never rant or rave. I, on the other hand, sit in front of the TV in torn underwear and drink beer out of the bottle. =====> OK, I know this FAQ is long. Very long. Well... it's ridiculously long. If you are inconvenienced or strenuously object to the posting of this FAQ, please DON'T FLAME me or send me nasty mail. Just think what I have to go through. This FAQ takes a lot of my time, of which I have very little to spare. I'm open for suggestions. I've considered the following: - splitting it up into smaller parts - eliminating certain sections which may no longer be relevant - the web and search engines certainly seem to make a lot of this FAQ obsolete (or am I mistaken on this?) - not posting it to the newsgroups and just turning this whole mess into a [large] web page (the problem with this is that I don't have a web site) - forgetting about it all together and reminding my kids that I'm their father (if you all tell me to go packing, I'll gladly fold up shop and devote more time to family, friends, and personal hygiene) I would be happy to hear ideas on how this FAQ could be improved for the reader. If it makes MY job easier, then that's even better. OK, with that out of the way, let's get on with it... Techno-Wimp, has announced the next generation of their wildly successful MIL (Mother-In-Law) transducer. Dubbed the MIL-II, it now includes Techno-Wimp's proprietary new breakthrough technology, MMX (Mad Mother-in-law Extensions). Utilizing patented heuristic algorithms, the MIL-II achieves a remarkable performance rating of 15 million MIPS (Mother-In-law Periphery Scans) per second. The previous WOMF ("Whoa, outta my face!") technology has been updated and improved, and together with MMX permits the MIL-II to concurrently detect multiple stimuli. This provides the designer with the necessary safety margin when using the MIL-II in mission critical applications. The MIL-II is implemented in Techno-Wimp's patented new fabrication technique, 0.25 micron JMOS (Jello Mold On Silicon). The MIL-II also features a new packaging technique called PSC/CEC (Plastic Slip Covers with Card Edge Connector). PSC/CEC was designed to allow easy upgrading to future products in the MIL transducer line. I hate it when I'm stupid, and well, I really did it this time. I omitted an important source of information - EDN magazine. Always full of timely features, important design articles, and the popular Design Ideas column. In addition, the 24th edition of the EDN microprocessor directory is due out this fall. This directory is an invaluable aid for designers. The EDN web site also has a lot of important information and software, and is improving all the time. Worth taking a look at: http://www.ednmag.com/ UMPS (Universal Microcontroller Program Simulator) is a new package from Virtual Micro Design in France. It simulates the following microcontrollers: 8051, 68HC705, PIC, ST62xx, and the 68HC11. The main feature of UMPS is the ability to build a virtual microcontroller board on screen by connecting various virtual resources (switches, LEDs, displays, A/D, D/A, I2C devices, logic functions, etc.) together with the desired processor. Then when debugging your software, you can see "real results" without having to worry about actually building the hardware. Processors that are not supported can be added by the user using Virtual Micro Design's toolkit. Additional virtual resources can be added by writing your own DLL to support the desired device. UMPS includes an integrated assembler/disassembler and debugger, extensive documentation on the supported processors. This is a very slick package. The English needs a lot of work, but the software itself is first class, easy to use, and incredibly powerful. For more information: Virtual Micro Design I.D.L.S. Technopole Izarbel 64210 BIDART FRANCE ++33-559-438-458 Fax: ++33-559-438-401 Email: p.techer@idls.izarbel.tm.fr If you'd like to start learning about microcontrollers, but the thought of finding all the parts and then building one scares you, take a look at the line of boards available from American Educational Systems. They have three boards: AES-51 (8051), AES-11 (68hc11), and AES-88 (8088). All three boards are built along the same lines and include RAM, ROM, LCD display, keypad, A/D, serial ports, digital I/O ports, and logic probe. Also included is a full bookshelf of documentation. These boards are ridiculously easy to use and program - you can get started experimenting right away. This is a perfect system for students and hobbyists. Even professionals will find this system useful as a prototyping tool and test bed. Highly recommended. For more information, contact: American Educational Systems 970 West 17th St. Santa Ana, CA 92706 USA (800)730-3232 or (714)550-8094 Fax: (714)550-9941 Check out Peter H. Anderson's web site. Lots of good microcontroller interfacing ideas and plans, PIC projects, and miscellaneous electronics. http://www.access.digex.net/~pha Barry Kauler, of GOOFEE fame, has done it again. He's written another RTOS, called CREEM. (He must stay up weeks thinking up names for this stuff. The names probably come to him in nightmares.) As hes says about this new system, "It's very unusual and very easy to use. It is probably the easiest way yet that anyone has come up with to do concurrent (multitasking) programming on a microcontroller." The first version is for the 8051 and is only 560 bytes and will run in a chip with only the internal RAM. Read the intro page and download CREEM (with source code) from the GOOFEE web site: http://www.goofee.com/creem.htm Point your browser at http://www.debco.com/ and take a look at what the gang at Debco has to offer. Lots of parts, kits, and assorted computer hardware. The best part is the series of Electronic Experimentors Journals that they've made available on-line. Chock full of project plans, ham radio topics (antennas and QRP), and computer questions and answers, these on-line journals are (IMHO) one of the highlights of the web. The gang at Debco should be commended. Recommended reading. Michael Dolinsky, Ph.D. and his team at Scaryna's Gomel State University in Belarus, have been doing research in embedded systems development tools. This research proposes methods, tools, and application results for integrated design of embedded hardware-software systems. Methods include tuning on selected hardware and designing hardware in parallel with the software. For information on this research, entitled, "High-Level Design Of Embedded Hardware-Software Systems", check out the following web sites: http://alcatraz.gmd.de:9422/castle/inter/inter.htm http://www.internet.no/kennethi/belarus/companies/sprl/ Their Inter Demo Version is available by anonymous ftp at: borneo.gmd.de (129.26.12.20) cd pub/SYDIS/inter Microtec announces a new quarterly newsletter, "Newbits" as a forum for their customers to share ideas: http://www.mri.com/newbits/newbits.html Take a peak at Magnus Danielson's collection of CPU stuff at: http://www.it.kth.se/~e93_mda/electronics/logic/cpu/ Good news... After reading about the 1 bit powerhouse (MC14500) in this FAQ, Christian Brunschen checked out Motorola's web site. "lo and behold I found,at <URL:http://mot-sps.com/books/sg379/pdf/comcomponents3rev6.pdf>, a document called 'Commercial Components' with a remark 'Effective date: July 5, 1997'. On page 5 (of 10) there is a line stating MC14500BCP CMOS 1-BIT ICU plus some codes, stating that this was a Proprietary device, part of something called the 'Phoenix Program', and that the $200 order minimum was waived -- but nothing about it being out of production. Rather, the'effective date' of july 5, 1997, would indicate that the chip is actually being produced as I am writing this. Also, the 'Phoenix Program' sounds like it could be some sort of 'let's revive some chips which we took out or production, just because' (Phoenix was the bird who died by fire every evening, and reborn from the ashes in the morning, if I recall correctly), so this could very well mean that production of this chip has been reinstated. Alas, I have not been able to find out any more info on Motorola's site as to what this 'Phoenix Program'_actually_ is." And you won't believe this, but Scott Finneran ALSO wrote about the 14500. Looks like we'll have to start a USENET newsgroup on this chip. Scott writes... "The Motorolla 14500 is alive and well down-under. I recently (about a year ago) performed some contract work for an Australian power station called Loy-Yang 'B'. They have a system manufactured in the early 1980's consisting of amongst other things hundreds of modules containing 14500 processors. These little beasts run at a whopping speed of 1KHz (liquid nitrogen coolant system was not necessary!!) and are used to control the start-up sequencing logic for firing up the power station boilers and turbines. The processor module in this system contained three 4-bit EPROMs in parallel (the early PICs were 12-bit I believe... spooky!). The first EPROM contained the op-code for the processor while the other two contained an 8-bit operand. Note: the operand was never fed into the processor (remember it is a single bit device) but directly out onto a parallel bus to select from a variety of digital inputs and outputs whose value was fed into the 1-bit data-bus of the processor. "My work involved reverse engineering their compiler to run on an MS-DOS platform. The "language" was basically boolean logic equations with little features such as software based flip-flops and hardware based timers. The compiler produced 14500 assembly language which was fed into the assembler that I also wrote as part of the package. With only sixteen instructions and 1 addressing mode, the assembler wasn't exactly a lot of work to produce. The system (and my compiler) are still in use today. The only problems are apparently the occasional timing capacitor goes dry in the 1KHz clock generator circuit (yes it's a 555)." Well, let's all scrap our '51 and hc11 projects and move to the 14500. Looks like we've got a trend here. Who knows, maybe Motorola will release a new generation 2-bit version? :-)) Embedded.com is the on-line union of three embedded information sources, Embedded Systems Programming Magazine, Miller Freeman Directories, and the Embedded Systems Conferences. There is no charge to users of this site, which contains hands-on articles, editorials, and code downloads. http://www.embedded.com Vasu Srinivasan recommends the book "Using the M68HC11 Microcontroller: A Guide to Interfacing and Programming" from Prentice-Hall. He says this book is useful if you're considering using the 68HC11EVB. See section 9.1 in this FAQ more information on this book. Take care of yourselves, Uncle Russ 1) ABOUT THIS FAQ 1.1) Who put this FAQ together? From time to time, general questions about microcontrollers and embedded processors (from beginners to experienced designers) pop up in the newsgroups. It seemed that a general primer/FAQ might be useful. Much of this document could be considered as a sort of a primer on microcontrollers, with some material on embedded processors being slowly added. For those of you with previous experience, sections 9 and 10 might be of special interest (especially for those of you looking for that elusive "free COBOL compiler for the 1802"). 1.2) How can I contribute to this list? I please ask that if you have any suggestions or additions, or you would like to correct any of the information contained herein, please send me a note. My Email address is: russ@shani.net My Smail address is: Russ Hersch HaVradim 11 Ginot Shomron ISRAEL Thanks to recent contributors: Magnus Danielson Marius Gafen (NSI, Israel) Michael Dolinsky, Ph.D. (Scaryna's Gomel State University, Belarus) Barry Kauler (the GOOFEE guy) Christian Brunschen Michael Markowitz (EDN magazine) Mark Meyer (American Educational Systems) Philippe Techer (Virtual Micro Design) Thomas Vegeby Ron Fredericks (editor, Software Forum Newsletter) Leticia Smith (webmaster, embedded.com) Bo Eriksson (Uppsala University, Sweden) Henry Spencer Mihai-Costin Manolescu Vasu Srinivasan Scott Finneran Tarjei T. Jensen John Doe (Techno-Wimp) Very special thanks to Robin L. Getz (National Semiconductor) who probably could be considered an honorary co-author of this FAQ. :-) Also, thanks to those who have posted questions and to those who have posted answers. Thanks to "all my net friends" who send suggestions and encouragement, as well as the occasional question. Special thanks to my mother-in-law, who thankfully doesn't know this FAQ exists ;-). 1.3) What newsgroups will this FAQ be posted to? This FAQ will be posted to the following newsgroups: comp.arch.embedded comp.robotics.misc comp.realtime sci.electronics.design alt.comp.hardware.homebuilt comp.answers sci.answers alt.answers news.answers I will post once a month - on or about the 26th of each month. 1.4) May I distribute this FAQ or post it somewhere else? I am putting no restrictions on the use of this FAQ except - It must be distributed in its entirety with the copyright notice, and no financial gain may be realized from it. After all, I have spent, and continue to spend, a lot of time on this. For this reason I have appended a copyright statement to the end of this FAQ. I feel pretty silly doing this, but I just want to protect myself. The copyright does not limit the use of this list for noncommercial purposes. I hereby give my permission to one and all to pass this list around and post it wherever you want - as long as it is not for financial gain. Thank you. 2) MICROCONTROLLERS AND EMBEDDED PROCESSORS 2.1) What is a Microcontroller? A controller is used to control (makes sense!) some process or aspect of the environment. A typical microcontroller application is the monitoring of my house. As the temperature rises, the controller causes the windows to open. If the temperature goes above a certain threshold, the air conditioner is activated. If the system detects my mother-in-law approaching, the doors are locked and the windows barred. In addition, upon detecting that my computer is turned on, the stereo turns on at a deafening volume (for more on this, see the section on development tools). At one time, controllers were built exclusively from logic components, and were usually large, heavy boxes (before this, they were even bigger, more complex analog monstrosities). Later on, microprocessors were used and the entire controller could fit on a small circuit board. This is still common - you can find many [good] controllers powered by one of the many common microprocessors (including Zilog Z80, Intel 8088, Motorola 6809, and others). As the process of miniaturization continued, all of the components needed for a controller were built right onto one chip. A one chip computer, or microcontroller was born. A microcontroller is a highly integrated chip which includes, on one chip, all or most of the parts needed for a controller. The microcontroller could be called a "one-chip solution". It typically includes: CPU (central processing unit) RAM (Random Access Memory) EPROM/PROM/ROM (Erasable Programmable Read Only Memory) I/O (input/output) - serial and parallel timers interrupt controller By only including the features specific to the task (control), cost is relatively low. A typical microcontroller has bit manipulation instructions, easy and direct access to I/O (input/output), and quick and efficient interrupt processing. Microcontrollers are a "one-chip solution" which drastically reduces parts count and design costs. 2.2) What is an embedded controller? Hah! Why not ask an easy question like "Did Adam have a navel?" or "Did Eve?" <Can't say about Adam, but well, Eve probably did. She would have looked pretty silly in a fig leaf, without a navel.> Simply (and naively stated) an embedded controller is a controller that is embedded in a greater system. A rigid definition is difficult if not impossible to formulate, since the usual response is "most embedded controllers are...". The problem here is "most". We can't seem to shake that word from the definition. No matter how clever you feel your definition is, some wiseguy will come along and find an exception, or two, or 50. You COULD say that an embedded controller is a controller (or computer) that is embedded into some device for some purpose other than to provide general purpose computing. Of course, someone will eventually prove you wrong, but who cares? A common example of a general purpose computer, would be a typical PC clone. The x86 processor in this machine can't really be considered an embedded controller, since the machine is typically used for general purpose computing. However, what is general purpose computing? Take this same PC clone, turn it into a multi-media machine, and voila! You have an appliance - much on the order of a microwave oven or television. Is the x86 processor now considered an embedded controller Or, is the PC clone itself now considered an embedded controller, controlling the multi-media peripherals? Hey - I don't know about you, but I'm getting too old for this nonsense. Is a microcontroller an embedded processor? Is an embedded processor a microcontroller? What's the difference between an embedded processor and a microcontroller? Well, today - not much. With the continuing process of high scale integration continuing at a dizzying pace, many standard architecture processors are turning up as microcontrollers. A few such examples are the Motorola 68EC300, Intel 386 EX, and the IBM PowerPC 403GB. These chips could be called super-microcontrollers. So, what's the difference between an embedded processor and a microcontroller? I wouldn't touch that question with a ten foot logic probe. We might be safe by stating that an embedded processor controls something (for example controlling a device such as a microwave oven, car braking system, or a cruise missile). Is this always true? Maybe. Maybe not. You know, it just doesn't end. The main thing is not to get to hung up on precise definitions. Black and white? Hell no, we've got grey scale, dithering, diffusion, you name it! Same thing goes here with embedded controllers, just go with the flow. It all depends on your point of view. Alright, if you really must insist, we'll take a stab at defining what an embedded controller is - realize however that there will be many exceptions. Embedded controllers adhere to a philosophy similar to that of microcontrollers, high integration. By including [many] features necessary for the task at hand, an embedded controller (processor) can be a powerful yet cost effective solution. However, where a microcontroller [almost by definition] is a computer on a chip, an embedded controller might need external components before it is considered a "computer." This is especially true regarding RAM. Since including large amounts of RAM (megabytes) on a processor is not really practical (due to cost and available silicon real estate) and because many embedded controllers are real powerhouses requiring large amounts of RAM, the RAM is often external to the processor. 2.3) Applications In addition to the above home monitoring system, embedded processors and microcontrollers are frequently found in: appliances (microwave oven, refrigerators, television and VCRs, stereos), computers and computer equipment (laser printers, modems, disk drives), automobiles (engine control, diagnostics, climate control), environmental control (greenhouse, factory, home), instrumentation, aerospace, and thousands of other uses. In many items, more than one processor can be found. Microcontrollers are typically used where processing power isn't so important. Although some of you out there might find a microwave oven controlled by a Unix system an attractive idea, controlling a microwave oven is easily accomplished with the smallest of microcontrollers. On the other hand, if you're putting together a cruise missile to solve the problem of your neighbor's dog barking at 3 in the morning, you'll probably need to use processors with a bit more computing power. Embedded processors and microcontrollers are used extensively in robotics. In this application, many specific tasks might be distributed among a large number of controllers in one system. Communications between each controller and a central, possibly more powerful controller (or micro/mini/mainframe) would enable information to be processed by the central computer, or to be passed around to other controllers in the system. A special application that microcontrollers are well suited for is data logging. Stick one of these chips out in the middle of a corn field or up in a ballon, and monitor and record environmental parameters (temperature, humidity, rain, etc). Small size, low power consumption, and flexibility make these devices ideal for unattended data monitoring and recording. 2.4) Flavors Embedded processors come in many flavors and varieties. Depending on the power and features that are needed, you might choose a 4, 8, 16, or 32 bit microcontroller. Standard microprocessors (such as the Motorola 68000 or National 32032) are frequently used as powerful embedded controllers. In addition, specialized processors are available which include features specific for communications, keyboard handling, signal processing, video processing, and other tasks. 3) THE MICROCONTROLLER MARKET Thanks to Robin Getz of National Semiconductor for supplying much of the material in this section. 3.1) Shipments WorldWide Microcontroller Shipments (in millions of dollars) '90 '91 '92 '93 '94 '95 '96 '97 '98 '99 '00 4-bit 1,393 1,597 1,596 1,698 1,761 1,826 1,849 1,881 1,856 1,816 1,757 8-bit 2,077 2,615 2,862 3,703 4,689 5,634 6,553 7,529 8,423 9,219 9,715 16-bit 192 303 340 484 810 1,170 1,628 2,191 2,969 3,678 4,405 WorldWide Microcontroller Shipments (in Millions) '90 '91 '92 '93 '94 '95 '96 '97 '98 '99 '00 4-bit 778 906 979 1036 1063 1110 1100 1096 1064 1025 970 8-bit 588 753 843 1073 1449 1803 2123 2374 2556 2681 2700 16-bit 22 38 45 59 106 157 227 313 419 501 585 Source: WSTS & ICE - 1994 If you were wondering why you should bother learning about microcontrollers - well, the tables above should fairly scream the answer at you. Microcontrollers will be *BIG* business - we're talking piles of cash - billions! Notice that even the lowly 4-bit device is holding its own - what use is a 16-bit part in a toaster oven? Also notice that the 8-bit market just keeps growing, and will probably continue to grow. 8-bit devices account for over half of the market, and will eventually grab even more. Now do you understand why every silicon manufacturer is really pushing their 8-bit microcontrollers? 3.2) Industrial applications Average Semiconductor Content per Passenger Automobile (in Dollars) '90 '91 '92 '93 '94 '95 '96 '97 '98 '99 '00 $ 595 634 712 905 1,068 1,237 1,339 1,410 1,574 1,852 2,126 Source: ICE - 1994 The automotive market is the most important single driving force in the microcontroller market, especially at it's high end. Several microcontroller families were developed specifically for automotive applications and were subsequently modified to serve other embedded applications. The automotive market is demanding. Electronics must operate under extreme temperatures and be able to withstand vibration, shock, and EMI. The electronics must be reliable, because a failure that causes an accident can (and does) result in multi-million dollar lawsuits. Reliability standards are high - but because these electronics also compete in the consumer market - they have a low price tag. Automotive is not the only market that is growing. DataQuest says that in the average North American's home there are 35 microcontrollers. By the year 2000 - that number will grow to 240. Consumer electronics is a booming business. 3.3) Deciding whose microcontroller to use When deciding which devices to implement in a design, there are lots of things to consider besides who else is using these devices (and how many are they using). - Can I expect help when I am having problems? - What development tools are available and how much do they cost? - What sort of documentation is available (reference manuals, application notes, books)? - Can I work a deal by purchasing more devices at one manufacturer? That is, purchasing not only the microcontroller, but also peripherals (A/D, memory, voltage regulator, etc.) from one company). - Do they support OTPs, windowed devices, mask parts? 3.4) The players MICROPROCESSORS Rank Sales ($ millions) 1995 1994 Company 1995 1994 ----------------------------------------------- 1 1 Intel $10,800 $8,036 2 3 AMD 881 992 3 2 Motorola 781 827 4 11 IBM 468 297 5 6 TI 219 202 6 4 Cyrix 210 240 7 5 Hitachi 188 66 8 7 NEC 100 82 9 8 LSI Logic 58 51 10 10 IDT 45 25 Source: In-Stat Inc. MICROCONTROLLERS Rank Sales ($ millions) 1995 1994 Company 1995 1994 ----------------------------------------------- 1 1 Motorola $1,781 $1,511 2 2 NEC 1,421 1,208 3 4 Mitsibishi 945 708 4 3 Hitachi 899 782 5 5 Intel 835 605 6 6 TI 807 534 7 8 Philips 524 345 8 7 Matsushita 500 413 9 10 Lucent (AT&T) 492 275 10 9 Toshiba 400 328 Source: In-Stat Inc. 4) MICROCONTROLLER FEATURES Thanks to Robin Getz of National Semiconductor who supplied some of the material in this section. 4.1) Fabrication techniques CMOS - Complementary Metal Oxide Semiconductor This is the name of a common technique used to fabricate most (if not all) of the newer microcontrollers. CMOS requires much less power than older fabrication techniques, which permits battery operation. CMOS chips also can be fully or near fully static, which means that the clock can be slowed up (or even stopped) putting the chip in sleep mode. CMOS has a much higher immunity to noise (power fluctuations or spikes) than the older fabrication techniques. PMP - Post Metal Programming (National Semiconductor) PMP is a high-energy implantation process that allows microcontroller ROM to be programmed AFTER final metalization. Usually ROM is implemented in the second layer die, with nine or ten other layers then added on top. That means the ROM pattern must be specified early in the production process, and completed prototypes devices won't be available typically for six to eight weeks. With PMP, however, dies can be fully manufactured through metalization and electrical tests (only the passivation layers need to be added), and held in inventory. This means that ROM can be programmed late in production cycle, making prototypes available in only two weeks. 4.2) Architectural features Von-Neuman Architecure Microcontrollers based on the Von-Neuman architecture have a single "data" bus that is used to fetch both instructions and data. Program instructions and data are stored in a common main memory. When such a controller addresses main memory, it first fetches an instruction, and then it fetches the data to support the instruction. The two separate fetches slows up the controller's operation. Harvard Architecture Microcontrollers based on the Harvard Architecture have separate data bus and an instruction bus. This allows execution to occur in parallel. As an instruction is being "pre-fetched", the current instruction is executing on the data bus. Once the current instruction is complete, the next instruction is ready to go. This pre-fetch theoretically allows for much faster execution than a Von-Neuman architecture, but there is some added silicon complexity. CISC Almost all of today's microcontrollers are based on the CISC (Complex Instruction Set Computer) concept. The typical CISC microcontroller has well over 80 instructions, many of them very powerful and very specialized for specific control tasks. It is quite common for the instructions to all behave quite differently. Some might only operate on certain address spaces or registers, and others might only recognize certain addressing modes. The advantages of the CISC architecture is that many of the instructions are macro-like, allowing the programmer to use one instruction in place of many simpler instructions. RISC The industry trend for microprocessor design is for Reduced Instruction Set Computers (RISC) designs. This is beginning to spill over into the microntroller market. By implementing fewer instructions, the chip designed is able to dedicate some of the precious silicon real-estate for performance enhancing features. The benefits of RISC design simplicity are a smaller chip, smaller pin count, and very low power consumption. Among some of the typical features of a RISC processor: - Harvard architecture (separate buses for instructions and data) allows simultaneous access of program and data, and overlapping of some operations for increased processing performance - Instruction pipelining increases execution speed - Orthogonal (symmetrical) instruction set for programming simplicity; allows each instruction to operate on any register or use any addressing mode; instructions have no special combinations, exceptions, restrictions, or side effects SISC Actually, a microcontroller is by definition a Reduced Instruction Set Computer (at least in my opinion). It could really be called a Specific Instruction Set Computer (SISC). The [original] idea behind the microcontroller was to limit the capabilities of the CPU itself, allowing a complete computer (memory, I/O, interrupts, etc) to fit on the available real estate. At the expense of the more general purpose instructions that make the standard microprocessors (8088, 68000, 32032) so easy to use, the instruction set was designed for the specific purpose of control (powerful bit manipulation, easy and efficient I/O, and so on). Microcontrollers now come with a mind boggling array of features that aid the control engineer - watchdog timers, sleep/wakeup modes, power management, powerful I/O channels, and so on. By keeping the instruction set specific (and reduced), and thus saving valuable real estate, more and more of these features can be added, while maintaining the economy of the microcontroller. 4.3) Advanced Memory options EEPROM - Electrically Erasable Programmable Read Only Memory Many microcontrollers have limited amounts of EEPROM on the chip. EEPROM seems more suited (becuase of its economics) for small amounts of memory that hold a limited number of parameters that may have to be changed from time to time. This type of memory is relatively slow, and the number of erase/write cycles allowed in its lifetime is limited. FLASH (EPROM) Flash provides a better solution than regular EEPROM when there is a requirement for large amounts of non-volatile program memory. It is both faster and permits more erase/write cycles than EEPROM. Battery backed-up static RAM Battery backed-up static RAM is useful when a large non-volatile program and DATA space is required. A major advantage of static RAM is that it is much faster than other types of non-volatile memory so it is well suited for high performance application. There also are no limits as to the number of times that it may be written to so it is perfect for applications that keep and manipulate large amounts of data locally. Field programming/reprogramming Using nonvolatile memory as a place to store program memory allows the device to be reprogrammed in the field without removing the microcontroller from the system that it controls. One such application is in automotive engine controllers. Reprogrammable non-volatile program memory on the engine's microcontroller allows the engine controller program to be modified during routine service to incorporate the latest features or to compensate for such factors as engine aging and changing emissions control laws (or even to fix bugs!!). Reprogramming of the microcontroller could become a standard part the routine engine tune-up. Almost every application could benefit from this type of program memory - If a modem's hardware supported it, you could remotely upgrade your modem from Vfast to V.34, or incorporate new features such as voice control or a digital answering machine. OTP - One Time Programmable An OTP is a PROM (Programmable Read-Only-Memory) device. Once your program is written into the device with a standard EPROM programmer, it can not be erased or modified. This is usually used for limited production runs before a ROM mask is done in order to test code. A OTP (One Time Programmable) part uses standard EPROM, but the package has no window for erasing. Once your program is written into the device with a standard EPROM programmer, it cannot be erased or modified. (Well, sort of - any bit that is a one can be changed to a zero - but a bit that is a zero cannot be changed into a one). As product design cycles get shorter, it is more important for micro manufacturers to offer OTPs as an option. This was commonly used for limited production runs before a ROM mask in order to test code. However, one problem with Mask ROM is that programming, setup, and engineering charges make it economical only when the systems manufacturer purchases large quantities of identically programmed micros. Then when you discover THAT bug (and find it and fix your code), you have quantities of *old buggy* micros around that you have to throw away. Not to mention that lead time (the time when you submit your code to the micro manufacture, to the time you receive your micro with your code on it) can be at least 8 weeks, and as bad as 44 weeks. Software protection Either by encryption or fuse protection, the programmed software is protected against unauthorized snooping (reverse engineering, modifications, piracy, etc.). This is only an option on OTPs and Windowed devices. On Masked ROM devices, security is not needed - the only way to read your code would be to rip the microcontroller apart with a scanning electron microscope - and how many people really have one of those? Although - and this is a manufacturer's little know fact - when a silicon manufacturer makes your ROMed microcontroller - they have to test it in order to make sure that it is programmed properly. (You should see what a spec of dust does on a mask :-) In order to test this, they must be able to read out the ROM and compare it to the code you submitted. This mode is known as test mode. IN TEST MODE YOU CAN READ OUT THE ROM OF ANY DEVICE. Anybody who tells you different, does not know what they are talking about - or is lying. This is usually not a big deal because test mode is ***VERY*** confidential, and (usually) only known by that manufacturer (i.e. you cannot put a device into test mode by accident). Test mode is ONLY applicable with ROMed devices. 4.4) Power Management and Low Voltage Low voltage parts Since automotive applications have been the driving force behind most microcontrollers, and 5 Volts is very easy to do in a car, most microcontrollers have only supported 4.5 - 5.5 V operation. In the recent past, as consumer goods are beginning to drive major segments of the microcontroller market, and as consumer goods become portable and lightweight, the requirement for 3 volt (and lower) microcontrollers has become urgent (3 volts = 2 battery solution / lower voltage = longer battery life). Most low voltage parts in the market today are simply 5 volt parts that were modified to operate at 3 volts (usually at a performance loss). Some micros being released now are designed from the ground up to operate properly at 3.0 (and lower) voltages, which offer comparable performance of the 5 volt devices. Now, why are voltages REALLY going down on ICs? Paul K. Johnson (of Hewlett-Packard) explains: There are a few interesting rules of thumb regarding transistors: 1) The amount of power they dissipate is proportional to their size. If you make a transistor half as big, it dissipates half as much power. 2) Their propagation delay is proportional to their size. If you make a transistor half as big, it's twice as fast. 3) Their cost is proportional to the square of their size. If you make them half as big, they cost one quarter as much. If you make a transistor smaller, you improve the power, speed, and cost. The only drawback is that they are harder to make. (Hey, how hard can it be for HP, IBM, Motorola, National, etc? ed.) Everybody in the world wants to make transistors smaller and smaller, the advantages are enormous. For years people have been using 5 Volts to power IC's. Because the transistors were large, there was little danger damaging the transistor putting this voltage across it. However, now that the transistors are getting so small, 5 Volts will actually fry them. The only way around this is to start lowering the voltage. This is why people are now using 3 (actually 3.3) Volt logic, and lower in the next few years. It isn't just because of batteries. Brownout Protection Brownout protection is usually an on-board protection circuit that resets the device when the operating voltage (Vcc) is lower than the brownout voltage. The device is held in reset and will remain in reset when Vcc stays below the Brownout voltage. The device will resume execution (from reset) after Vcc has risen above the brownout Voltage. Idle/Halt/Wakeup The device can be placed into IDLE/HALT mode by software control. In both Halt and Idle conditions the state of the microcontroller remains. RAM is not cleared and any outputs are not changed. The terms idle and halt often have different definitions, depending on the manufacturer. What some call idle, others may call halt, and vice versa. It can be confusing, so check the data sheet for the device in question to be sure. In IDLE mode, all activities are stopped except: - associated on-board oscillator circuitry - watchdog logic (if any) - the clock monitor - the idle timer (a free running timer) Power supply requirements on the microcontroller in this mode are typically around 30% of normal power requirements of the microprocessor. Idle mode is exited by a reset, or some other stimulus (such as timer interrupt, serial port, etc.). A special timer/counter (the idle timer) causes the chip to wake up at a regular interval to check if things are OK. The chip then goes back to sleep. IDLE mode is extremely useful for remote, unattended data logging - the microprocessor wakes up at regular intervals, takes its measurements, logs the data, and then goes back to sleep. In Halt mode, all activities are stopped (including timers and counters). The only way to wake up is by a reset or device interrupt (such as an I/O port). The power requirements of the device are minimal and the applied voltage (Vcc) can sometimes be decreased below operating voltage without altering the state (RAM/Outputs) of the device. Current consumption is typically less than 1 uA. A common application of HALT mode is in laptop keyboards. In order to have maximum power saving, the controller is in halt until it detects a keystroke (via a device interrupt). It then wakes up, decodes and sends the keystroke to the host, and then goes back into halt mode, waiting either for another keystroke, or information from the host. Multi-Input Wakeup (National Semiconductor) The Multi-Input WakeUp (MIWU) feature is used to return (wakeup) the microcontroller from either HALT or IDLE modes. Alternately MIWU may also be used to generate up to 8 edge selectible external interrupts. The user can select whether the trigger condition on the pins is going to be either a positive edge (low to high) or a negative edge (high to low). 4.5) I/O UART A UART (Universal Asynchronous Receiver Transmitter) is a serial port adapter for asynchronous serial communications. USART A USART (Universal Synchronous/Asynchronous Receiver Transmitter) is a serial port adapter for either asynchronous or synchronous serial communications. Communications using a USART are typically much faster (as much as 16 times) than with a UART. Synchronous serial port A synchronous serial port doesn't require start/stop bits and can operate at much higher clock rates than an asynchronous serial port. Used to communicate with high speed devices such as memory servers, display drivers, additional A/D ports, etc. Can also be used to implement a simple microcontroller network. SPI (Motorola) An SPI (serial peripheral interface) is a synchronous serial port. SCI An SCI (serial communications interface) is an enhanced UART (asynchronous serial port). I2C bus - Inter-Integrated Circuit bus (Philips) The I2C bus is a simple 2 wire serial interface developed by Philips. It was developed for 8 bit applications and is widely used in consumer electronics, automotive and industrial applications. In addition to microcontrollers, several peripherals also exist that support the I2C bus. The I2C bus is a two line, multi-master, multi-slave network interface with collision detection. Up to 128 devices can exist on the network and they can be spread out over 10 meters. Each node (microcontroller or peripheral) may initiate a message, and then transmit or receive data. The two lines of the network consist of the serial data line and the serial clock line. Each node on the network has a unique address which accompanies any message passed between nodes. Since only 2 wires are needed, it is easy to interconnect a number of devices. MICROWIRE/PLUS (National Semiconductor) MICROWIRE/PLUS is a serial synchronous bi-directional communications interface. This is used on National Semiconductor Corporation's devices (microcontrollers, A/D converters, display drivers, EEPROMS, etc.). CAN & J1850 CAN (Controller Area Network) is a mutiplexed wiring scheme that was developed jointly by Bosh and Intel for wiring in automobiles. J1850 is the SAE (Society of Automotive Engineers) multiplexed automotive wiring standard that is currently in use in North America. Both of these groups have the "NOT INVENTED HERE" syndrome and refuse to work with each other's standard. The standards are quite different and are not compatible at all. The CAN specification seems to be the one that is being used in industrial control both in North American and Europe. With lower cost microcontrollers that support CAN, CAN has a good potential to take off. Ken Tindell points out that although the J1850 and CAN buses are incompatible at an electrical level, they are almost the same at a higher level. They both use short-frame priority arbitration based on 29-bit identifiers. At a software-level there is hope. Isn't there always? Analog to Digital Conversion (A/D) Converts an external analog signal (typically relative to voltage) and converts it to a digital representation. Microcontrollers that have this feature can be used for instrumention, environmental data logging, or any application that lives in an analog world. The various types of A/D converters that can be found: Succesive Approximation A/D converters -- This the most common type of A/D and is used in the majority of microcontrollers. In this technique, the converter figures out each bit at a time (most significant first) and finds if the next step is higher or lower. This way has some benefits - it takes exactly the same amount of time for any conversion - it is very common - (and therefore very cheap). However it also has some disadvantages - it is slow - for every bit it takes at least one clock cycle - the best an 8-bit A/D can do is at least 8 clock cycles (and a couple for housekeeping). Because it takes so long - it is a power hog as compared to the other types of A/Ds. Single Slope A/D converters -- This is the type of converter that you can build yourself (if the microcontroller has a couple of analog blocks on it). Your single slope A/D converter would include Analog Mux / comparator / timer (8-bit timer = 8 bit A/D - 16-bit timer = 16 bit A/D) with input capture and a constant current source. The only microcontroller (that I know of) that has all of this on it is National's COP888EK. First Step is to clear the timer to 0000 and then start it. It is a simple matter to hang an external capacitor, and charge it with the constant current source (linearly because of the current source) when the voltage on the cap exceeds the sampling voltage, the comparitor toggles, stops the timer - and voila - you have the voltage in uSecs - with 16-bit accuracy. The only drawback is you can't really expect 16 bits (14 yes) - the conversion time varies quite a bit, and it is SLOW. Delta-Sigma A/Ds converters -- This type of A/D converter is found on higher-end DSPs. These are the hardest to understand of the A/Ds because it just makes a best guess (a little National Semiconductor humor here :-). Delta sigma A/Ds can be broken down into two main parts. The modulator which does the A/D conversion and the filter, which turns the output of the modulator into a format suitible for the microcontroller (or DSP). The modulator is very simple - it just compares the input voltage to the average of the last 100 (or so) modulator outputs and decides if the input is higher or lower than the average. This happens millions of times a second, resulting in a high speed single-bit datastream of 1s and 0s who's *average* is equal to the input voltage. Becuse the ouput is only a one or a zero, there are very few sources of errors. This is the main reason that delta-sigma A/Ds are **very** accurate. The filter comes after the modulator ... and this filter is essentially a big DSP block. It must take the very high speed stream of ones and zeros and turn it into a slower speed stream of 16-bit (or greater) words to be used by the microcontroller. This process is called decimation and the filter is often called a "comb filter". Another digital filter follows this stage and rejects unwanted frequencies. This filter performs a similar function to the anti-aliasing filter required in many traditional A/D appliactions, but it does it at an unprecedented level of performance and at low cost. This is the other major benefit of delta-sigma A/Ds. Flash A/D -- This is the basic architecure for the fastest category of A/Ds. The flash converter involves looking at each level that is possible and instantaneously saying what level the voltage is at. This is done by setting up comparators as threshold detectors with each detector being set up for a voltage exaclty 1 LSB higher than the detector below it. The benefit of this architecture is that with a single clock cycle, you can tell exactly what the input voltage is - that is why it is so fast. The disadvantage is that to achieve 8-bit accuracy you need 256 comparators and to achieve 10-bit accuracy you need 1024 comparators. To make these comparators operate at higher speeds, they have to draw LOTS of current, and beyond 10 bits, the number of comparators required becomes totally unmanageable. D/A (Digital to Analog) Converters This feature takes a Digital number and converts it to a analog output. The number 50 would be changed to the analog output of (50/256 * 5Volts) = .9765625V on a 8-bit / 5 Volt system. Pulse width modulator Often used as a digital-to-analog conversion technique. A pulse train is generated and regulated with a low-pass filter to generate a voltage proportional to the duty cycle. Pulse accumulator A pulse accumulator is an event counter. Each pulse increments the pulse accumulator register, recording the number of times this event has occurred. Input Capture Input Capture can measure external frequencies or time intervals by copying the value from a free running timer into a register when an external event occurs. Comparator One or more standard comparators can sometimes be placed on a microcontroller die. These comparators operate much like standard comparators however the input and output signals are available on the microcontroller bus. Mixed (Analog-Digital) Signal We live in an analog world where the information we see, hear, process, and exchange with each other, and with our mechanical and electronic systems, is always an analog quantity - pressure, temperature, voltage, current, air and water flow are always analog entities. They can be digitized for more efficient sorting, storage and transmittal, but the interface - the input and output - is almost always analog. Thus the essence of analog electronics lies in sensing continuously varying information, shaping and converting it for the efficiency of digital processing and transmission, and reshaping the digital data to an analog signal at the other end. Mixed analog-digital devices are being used increasingly to integrate the complex functions of high-speed telecommunications, or the real-time data processing demanded by industrial control systems and automotive systems. Start looking for microcontrollers that have analog comparators, analog multiplexers, current sources, voltage doublers, PLL (Phase Lock Loops) and all sorts of peripherals that you thought were analog only. 4.6) Interrupts Polling Polling is not really a "feature" - it's what you have to do if your microcontroller of choice does not have interrupts. Polling is a software technique whereby the controller continually asks a peripheral if it needs servicing. The peripheral sets a flag when it has data ready for transferring to the controller, which the controller notices on its next poll. Several such peripherals can be polled in succession, with the controller jumping to different software routines, depending on which flags have been set. Interrupts Rather than have the microcontroller continually polling - that is, asking peripherals (timers / UARTS / A/Ds / external components) whether they have any data available (and finding most of the time they do not), a more efficient method is to have the peripherals tell the controller when they have data ready. The controller can be carrying out its normal function, only responding to peripherals when there is data to respond to. On receipt of an interrupt, the controller suspends its current operation, identifies the interrupting peripheral, then jumps (vectors) to the appropriate interrupt service routine. The advantage of interrupts, compared with polling, is the speed of response to external events and reduced software overhead (of continually asking peripherals if they have any data ready). Most microcontrollers have at least one external interrupt, which can be edge selectible (rising or falling) or level triggered. Both systems (edge/level) have advantages. Edge - is not time sensitive, but it is susceptible to gitches. Level - must be held high (or low) for a specific duration (which can be a pain - but is not susceptible to glitches). Interrupts are critical when you are controlling anything (this is what microcontrollers do). If you misunderstand any of the terms, and design your systems with the way you *think* it works - not the way it *really* works - it will effect system performance. It may also work for a very long time with no problems, and then all of a sudden fail. Check your datasheets - these descriptions are the correct ones (or are at least supposed to be), but that does not mean that they are agreed to by the silicon manufacturers, (or by the marketing guys that they employ, and who write parts of the data sheets.) 4 bit microcontrollers usually have either a polling or non-vectored type of interrupt scheme. 8 and 16 bit microcontrollers usually have some type of vectored arbitration type of interrupt scheme. 32 bit microcontrollers usually will have some type of vectored priority type of interrupt scheme. Again, check your data sheet to make sure - or ask a manufacturer's rep if you aren't sure. Maskable Interrupts A maskable interrupt is one that you can disable or enable (masking it out means disabling the interrupt), whereas non-maskable interrupts you can't disable. The benefit of maskable interrupts is that you can turn off a particular interrupts (for example a UART) during some time critical task. Then, those particular interrupts will be ignored thus allowing the microcontroller to deal with the task at hand. Most microcontrollers (as well as most microprocessors) have some type of Global Interrupt Enable (GIE) which allows you to turn off (or on) all of the maskable interrupts with one bit. NOTE: GIE usually does not effect any NMI (Non-Maskable Interrupts) Vectored Interrupts Simple (non-vectored) interrupts is one of the simplest interrupt schemes there is (Simple = less silicon = more software = slower). Whenever there is an interrupt, the program counter (PC) branches to one specific address. At this address, the system designer needs to check the interrupts (one at a time) to see which peripheral has caused the interrupt to occur. Code for this may look like (on a COP8): IFBIT UART,PSW ; If the UART bit has been set JP UART_Recieve ; Jump to the UART receive service routine IFBIT T1,PSW ; If the timer has underflowed JP Underflow ; Jump to the underflow service routine ... and so on This can be *very* slow - and the time between the interrupt happening and the time the service routine is entered, depends on how the system designer sets up their ranking. The peripheral that is checked last takes the longest to process. Most microcontrollers that have fewer than 3 - 5 interrupts use this method. The benefit of this is that the system designer can set the priority - The most important peripheral gets checked first - and you get to decide which peripheral that is. Vectored interrupts are a little easier to set up, but the system designer has less control of the system (i.e. is dependent on the silicon manufacture to make the proper decisions during design of the chip). When an interrupt occurs, the hardware interrupt handler automatically branches to a specific address depending on what interrupt occurred. This is much faster than the non-vectored approach described above, however the system designer does not get to decide what peripheral gets checked first. Example (on a National Semiconductor COP888CG): Rank Source Description Vector Address ------------------------------------------------------------------ 1 (highest) Software INTR Instruction 01FE - 01FF 2 External Pin G0 Edge 01FA - 01FB 3 Timer T0 Underflow 01F8 - 01F9 4 Timer T1 T1A / Underflow 01F6 - 01F7 5 Timer T1 T1B 01F4 - 01F5 6 MICROWIRE/PLUS BUSY Goes Low 01F2 - 01F3 7 UART Receive 01EE - 01EF 8 UART Transmit 01EC - 01ED 9 Timer T2 T2A / Underflow 01EA - 01EB 10 Timer T2 T2B 01E8 - 01E9 11 Timer T3 T3A / Underflow 01E6 - 01E7 12 Timer T3 T3B 01E4 - 01E5 13 Port L / MIWU Port L Edge 01E2 - 01E3 14 (lowest) Default VIS Interaction 01E0 - 01E1 In ROM location 01F8 - 01F9 (2bytes x 8 bits = 16bit address) the system designer enters the ROM location of where they want the service routine (of the Timer T0 underflow) to be. And so on for the rest of the addresses. Interrupt arbitration and priority Interrupt arbitration and priority - These are two of the most misused words when it comes to microcontrollers (microprocessors too for that matter) and it's generally because no one knows the difference between them. Priority is not Arbitration. Arbitration is not Priority. Lets see if we can sort out the differences. Arbitration - If you look at the above chart of the COP888CG, you may think the interrupts are prioritized because they have some ranking. They do have rank, but they are not prioritized. What happens is that (in an arbitration scheme) when an interrupt occurs, the GIE (Global Interrupt Enable) is cleared. This effectively means that all future interrupts will be delayed until the GIE is set. The GIE becomes set only if the system designer sets it in a service routines, or on a RETI (Return from Interrupt). Quick Example 1 - Timer 1 underflows - the hardware clears the GIE, looks at ROM locations 01F6 and 01F7 and jumps to the ROM location pointed to by those addresses. The program does a couple things, and then sets the GIE (because the user wants to recognize an external interrupt during this service routine). However while in the service routine, Timer 3 underflows. Although a timer 3 underflow is lower in rank than a timer 1 underflow, the interrupt handler does not care - it simply looks at the GIE, and because it is set - handles the interrupt (now we have nested interrupts). The Timer 1 underflow service routine will not be completed until the Timer 3 underflow is complete. Quick Example 2 - Timer 3 underflows at the same time as an External interrupt occur. The one to be handled first is the External Interrupt. If the user sets the GIE, the interrupt handler will jump down to the Timer 3 underflow handler. If the user does not set the GIE, the microcontroller handles the External interrupt, does a RETI, and the Timer 3 underflow can now be handled. Priority - In a priority scheme, things are prioritized (well, what'd you expect?). If Timer T0 underflows, the only thing that can interrupt that is an external or software interrupt. If a external or software interrupt occurs, the interrupt handler will branch to these service routines. When they are complete, it will return to the Timer T0 underflow. Quick Example - In the below timing diagram, the following happens: 1) Timer T0 underflows 2) Timer T2 underflows 3) An External Interrupt occurs. In a priority scheme, the following would happen: External Interrupt |---------| | | Timer T0 Underflow |-------| |------| | | Timer T2 Underflow | |------| | | Normal Execution ---| |------- ^ ^ ^ ^ ^ ^ | | | | | | Time -> | | | | | \-T2 Done | | | | \-------- T0 Done | | | \-------------- Ext Done | | \------------------------ Ext Edge | \----------------------- T2 Underflows \--------------------------- T0 Underflows This is what RTOS (Real Timer Operating Systems) do - prioritize and handle interrupts. 4.7) Special microcontroller features Watchdog timer A watchdog timer provides a means of graceful recovery from a system problem. This could be a program that goes into an endless loop, or a hardware problem that prevents the program from operating correctly. If the program fails to reset the watchdog at some predetermined interval, a hardware reset will be initiated. The bug may still exist, but at least the system has a way to recover. This is especially useful for unattended systems. Digital Signal Processors (DSP) Microcontrollers react to and control events - DSPs execute repetitive math-intensive algorithms. Today many embedded applications require both types of processors, and semiconductor manufacturers have responded by introducing microcontrollers with on-chip DSP capability and DSPs with on-chip microcontrollers. The most basic thing a DSP will do is a MACC (Multiply and ACCumulate). The number of data bits a DSP can Multiply and ACCumulate will determine the dynamic range (and therefore the application). Bits Fixed/Floating Dynamic Range Typical Application 8 Fixed 48 dB Telephone-quality voice 16 Fixed 96 dB Compact disk (marginal) 24 Fixed 144 dB Compact disk (room for error) Clock Monitor A clock monitor can shut the microcontroller down (by holding the microcontroller in reset) if the input clock is too slow. This can usually be turned on or off under software control. Resident program loader Loads a program by Initializing program/data memory from either a serial or parallel port. Convenient for prototyping or trying out new features, eliminates the erase/burn/program cycle typical with EPROMs, and allows convenient updating of a system even from an offsite location. Monitor A monitor is a program installed in the microcontroller which provides basic development and debug capabilities. Typical capabilities of a microcontroller monitor include: loading object files into system RAM, executing programs, examining and modifying memory and registers, code disassembly, setting breakpoints, and single-stepping through code. Some simple monitors only allow basic functions such as memory inspection, and the more sophisticated monitors are capable of a full range of debug functions. Monitors can either communicate with a dumb terminal or with a host computer such as a PC. Much of the work of the monitor (such as user interface) can be offloaded to the host PC running a program designed to work with the monitor. This makes it possible to reduce the size and complexity of the code that must be installed in the target system. MIL transducer An MIL transducer is a sophisticated and expensive device that detects the presence of your mother-in-law. Sensitivity settings are possible for a full range of stimuli such as: snarling, stomping, nasty faces, and others. Techno-Wimp (address withheld upon request), the sole manufacturer of the MIL transducer, has recently announced a major new version which is sensitive enough to detect less-tangible stimuli. This breakthrough product is dubbed the MIL-WOMF ("Whoa, outta my face!") transducer. Both the original MIL and the new MIL-WOMF transducers are programmable and easy to interface to most microcontrollers. 5) Some popular microcontrollers Some common microcontrollers are described below. A common question is "what microcontroller should I use for...?" Well, that's a tough one. The best advice would be to choose a chip that has a full set of development tools at the price you can afford, and good documentation. For the hobbyist, the Intel 8051, Motorola 68hc11, or Microchip PIC would all make suitable choices. 8048 (Intel) The grandaddy of 'em all, the first microcontroller, it all started here! Although a bit long in the tooth and a bit kludgey in design (at least by today's standards), it is still very popular due to its very low cost, availability, and wide range of development tools. Modified Harvard architecture with program ROM on chip with an additional 64 to 256 bytes of RAM also on chip. I/O is mapped in its own space. 8051 (Intel and others) The 8051, Intel's second generation of microcontrollers, rules the microcontroller market at the present time. Although featuring a somewhat bizarre design, it is a very powerful and easy to program chip (once you get used to it). Modified Harvard architecture with separate address spaces for program memory and data memory. The program memory can be up to 64K. The lower portion (4K or 8K depending on type) may reside on chip. The 8051 can address up to 64K of external data memory, and is accessed only by indirect addressing. The 8051 has 128 bytes (256 bytes for the 8052) of on-chip RAM, plus a number of special function registers (SFRs). I/O is mapped in its own space. The 8051 features the so-called "boolean processor". This refers to the way instructions can single out bits just about anywhere (RAM, accumulators, I/O registers, etc.), perform complex bit tests and comparisons, and then execute relative jumps based on the results. Piles of software, both commercial and free, are available for the 8051 line. Many manufacturers supply what must be a hundred different variants of this chip for any requirement. Often featured in construction projects in the popular hobbyist magazines. 80c196 (MCS-96) The third generation of Intel microprocessors, the 80c196 is a 16 bit processor. Originally fabricated in NMOS (8096), it is now mainly available in CMOS. Intel Corp. has recently introduced a clock-doubled (50MHz) version of the 80c196. Among the many features it includes are: hardware multiply and divide, 6 addressing modes, high speed I/O, A/D, serial communications channel, up to 40 I/O ports, 8 source priority interrupt controller, PWM generator, and watchdog timer. 80186,80188 (Intel) These chips are, in essence, microcontroller versions of the 8086 and 8088 (of IBM/PC fame). Included on the chip are: 2 channels of DMA, 2 counter/timers, programmable interrupt controller, and dynamic RAM refresh. There are several variations including: low power versions, variations with serial ports, and so on. One major advantage you gain by using one of these parts is that you can use standard PC development tools (compilers, assemblers, etc) for developing you applications. If you are already familiar with PC software development, the learning curve will be short, since these chips have the same basic architecture as the original 8088 (as used in the IBM/PC). Other advantages include high speed processing, a full megabyte addressing space, and powerful interrupt processing. 80386 EX (Intel) The 80386 EX is of course a 386 in microcontroller clothing. Included on the chip are: serial I/O, power management, DMA, counter/timers, programmable interrupt controller, and dynamic RAM refresh. And of course, all of the power of the 386 microprocessor. One major advantage you gain by using one of these parts is that you can use standard PC development tools (compilers, assemblers, etc) for developing your applications. If you are already familiar with PC software development, the learning curve will be short, since these chips have the same basic architecture as the original 8088 (as used in the IBM/PC). We're talking power here gang. Now let's all wait for Microsoft to release a version of Windows for embedded and real-time applications (Windows ET? Windows RT? Windows 2000? :-). 65C02/W65C816S/W65C134S (Western Design Center) The Western Design Center, Inc. is the original owner and designer of the 65C02 8-bit microprocessor, used in the original Apple, Commodore, and Atari computers. WDC has subsequently developed a 16-bit MPU (W65C816S), an 8-bit microcontroller (with 65C02 as the core) named W65C134S, and a 16-bit microcontroller (with 65C816 as core). These are sold off-the-shelf and the the module technology is licensed for use in ASIC designs. WDC has recently come out with their .8u 134S and 265S. There are many companies who have or are designing in these parts into their board-level system design. It is expected that this new version's performance to be greatly enhanced over the previous 1.2u. They are also working with their foundry to add EE and Flash versions to their standard product offering. The Western Design Center 2166 East Brown Rd. Mesa, AZ 85213 (602)962-4545 Fax: (602)835-6442 Email: wdesignc@wdesignc.com Web: http://www.wdesignc.com MC14500 (Motorola) According to Magnus Danielson, "This is an awesome chip that everyone should know by heart... why? It's so weird compared to most other chips... it is really worth reading up on the details. It lives its life inside a 16 pin DIP and has 16 instructions." Motorola was the manufacturer of this 1 bit powerhouse, which is now out of production. And no, there isn't a C compiler for it. Maybe Dave Dunfield (hi Dave ;-) wouldn't mind adding this to his C compiler suite. Although the MC14500 is a bit bizarre (one bit's worth) and may be somewhat limited, it does have a few noteworthy features: - RISC processor with 16 instructions (well, what did you expect from a 1 bit processor) and one addressing mode - no memory boundary (an infinite amount of memory) - small package (16 pin) Find a copy of the data sheet on this chip and give it a careful going over. I'm sure you'll agree that this was an interesting chip and I imagine was probably quite useful. Seems to me that the new wave of scaled-down micros such as the Atmel 2051, MicroChip PIC, and Philips 752 probably caused its demise. 68HC05 (Motorola) The 68HC05 (and the earlier 6805) is based loosely on the manufacturer's earlier 6800, with some similarities to the 6502. It has a Von-Neuman architecture in which instructions, data, I/O, and timers all share the same space. Stack pointer is 5 bits wide which limits the stack to 32 bytes deep. Some members of this family include on chip A/D, PLL frequency synthesizer, serial I/O, and software security. 68hc11 (Motorola and Toshiba) The popular 68hc11 is a powerful 8-bit data, 16-bit address microcontroller from Motorola (the sole supplier) with an instruction set that is similar to the older 68xx parts (6801, 6805, 6809). The 68hc11 has a common memory architecture in which instructions, data, I/O, and timers all share the same memory space. Depending on the variety, the 68hc11 has built-in EEPROM/OTPROM, RAM, digital I/O, timers, A/D converter, PWM generator, pulse accumulator, and synchronous and ansynchronous communications channels. Typical current draw is less than 20ma. 683xx (Motorola) The MC68EC300 series incorporates various peripherals into various 68k family core processors. These can be called "integrated processors". They are really super-microcontrollers, very high performance, capable of high processing speeds, and able to address large amounts of memory. A typical example from this line would be the 68331. It is based on a 68020-like core and has about the same processing power as an Intel 80386. PIC (MicroChip) While watching my 8 year old daughter play with her Barbie Dolls (she has about 7 or so, including two that used to belong to Roz, my wife, when she was a girl) I noticed an interesting difference between the old dolls and the new dolls. The old Barbies could only move their heads sideways, while the new Barbies not only can move their heads sideways, but also up and down. AMAZING - the old Barbies were good girls - they could only say no. The new Barbies however can also say yes. Progress - isn't it wonderful! (Not to mention the gymnast Barbie that Dave Perry's daughter got for Christmas - "wait'll you see what *she* can do ;-)" Which leads me to an amazing fact. Most everyone thinks of the PIC microcontroller line as being a recent introduction. However, they've been popular for over 20 years. What's the difference? Microchip (which was originally [owned by] General Instruments), seems to have recreated this microcontroller into a product universally regarded as a powerful and cost effective solution. The new chips are fabricated in CMOS, some features have been added, and new family lines have been introduced. The PIC microcontrollers were the first RISC microcontrollers. RISC generally implies that simplicity of design allows more features to be added at lower cost, and the PIC line is no exception. Although having few instructions (eg. 33 instructions for the 16C5X line versus over 90 for the Intel 8048), the PIC line has a wealth of features included as part of the chip. Separate buses for instructions and data (Harvard architecture) allows simultaneous access of program and data, and overlapping of some operations for increased processing performance. The benefits of design simplicity are a very small chip, small pin count, and very low power consumption. PIC microcontrollers are rapidly gaining in popularity. They are being featured more and more often in construction projects in popular hobbyist magazines, and are chalking up a good number of design wins. Due to their low cost, small size, and low power consumption, these microcontrollers can now be used in areas that previously wouldn't have been appropriate (such as logic circuits). They are currently available in three lines: the PIC16C5x, PIC16Cxx, and PIC17Cxx families. PSST! Hey kid! Want a naked Barbie Doll?! Henry Spencer adds the following information: The 16C5x line is the descendant of the original PIC design; they are a bit limited and clumsy, and have essentially been made obsolete by the 16Cxx. The 16Cxx line is the heart of the PIC family today, an improved design benefitting from hindsight: tidier and more flexible than the 16C5x while retaining its simplicity and speed, and providing a wide spread of prices and capabilities, including quite a few choices of on-chip peripherals. The 17Cxx line is more ambitious, arguably pushing the PIC architecture rather farther than God intended :-) it to go; they can do things the 16Cxx line can't, but they're not where most of the action is. Unusually for microcontrollers, the Microchip PIC databooks include complete documentation on how to program the chips -- information that other manufacturers often will give out only to programmer manufacturers, only under nondisclosure, or only at gunpoint. COP400 Family (National Semiconductor) The COP400 Family is a P2CMOS 4-bit microcontroller which offers 512 bytes to 2K ROM and 32x4 to 160x4 RAM. Packages are varied from 20 to 28 pin (DIP/SO/PLCC). Functions include Microwire, timers counters, 2.3 to 6.0 Volt operation, ROMless modes, and OTP support. Far from being "old" technology - 4-bit microcontrollers are meeting significant market needs in more applications than ever before. The reason for the continuing strength of the COP400 family is its versatility. Over 60 different, compatible devices are available for a wide range of requirements. The first under $.50 microcontroller set a new standard of value for cost/performance. COP800 Family (National Semiconductor) The COP800 Basic Family is a fully static 8-bit microcontroller, fabricated using double metal silicon gate microCMOS technology. This low cost microcontroller contains all system timing, interrupt logic, ROM, RAM, and I/O necessary to implement dedicated control functions in a variety of applications. Depending on the device, features include: 8-bit memory mapped architect, MICROWIRE serial I/O, UART, memory mapped I/O, many 16 bit timer/counters with capture registers, a multi-sourced vectored interrupt, comparator, WATCHDOG Timer and Clock monitor, Modulator/Timer (high speed PWM timer for IR transmission), 8-channel A/D converter with prescaler and both differential and single-ended modes, brownout protection, halt mode, idle mode, high current I/O pins with 15mA sink capability, Schmitt trigger inputs and Multi-Input-Wake-Up. Most devices operate over a voltage range from 2.5V to 6V. High throughput is achieved with an efficient, powerful instruction set operating at a 1uS per instruction rate (most instructions are single byte/single cycle) including true bit manipulation and BCD arithmetic instructions. Most devices have military versions for -55C to +125C. HPC Family (National Semiconductor) The HPC Family of High Performance microControllers is a 16-bit controller fabricated using National's advanced microCMOS technology. This process combined with an advanced architecture provides fast, flexible I/O control, efficient data manipulation, and high speed computation. With its 16x16 bit multiply and 32x16 bit divide, the HPC is appropriate for compute-intensive environments that used to be the sole domain of the microprocessor. The architecture is a Von-Neuman architecture where the program and data memory share the same address space. Depending on the family member, features include: 16-bit memory-mapped architecture with software configurable external address/data bus, Microwire/Plus serial I/O, UART, 16-bit timer/counters with input capture capability, High-Level Data Link Control (HDLC) for ISO-standard data communications, 8-channel A/D converter with prescaler and both differential and single-ended modes, power-saving modes, Multiply/Accumulate Unit with built-in circular buffer management for low to medium DSP applications, software configurable chip-select outputs, 64KB address space directly addressable, low-voltage (3.3V) operation. High throughput is achieved with an efficient, powerful instruction set operating at a 50ns per instruction cycle (most instructions are single byte/single cycle) including true bit manipulation. Key applications currently using the HPC family include: Anti-lock Braking Systems, Hard Disk drives for mass storage, telecommunications, security systems, laser printers, and some military applications. Project Piranha (National Semiconductor) Project Piranha is an internal code name for National Semiconductor's embedded RISC processor technology. The Piranha technology represents the first RISC processor specifically designed for the needs of embedded applications. This was accomplished through examination of the needs of typical embedded applications, resulting in a technology which maintains the benefits of CISC while providing the performance of RISC. Specifically, some of these benefits are: compact code density --> smaller memory usage/ lower system cost small core size --> more room for add-on system design scalable architecture --> a range of performance solutions from 8 to 64 bits with a common architecture common instruction set --> you only face the learning curve and development tools once modular design --> designed for easy integration of specialized functions into single chip This technology is initially being implemented in application specific products from National Semiconductor, with the first product being available in Q1, 1995. For further information on this technology, please contact Mark Throndson at tmetsc@esd.nsc.com, or (408) 721-4957. Z8 (Zilog) A "loose" derivative of the Zilog Z80, the Z8 is actually a composite of several different achitectures. Not really compatible with the Z80 peripherals. Has a unique architecture with three memory spaces: program memory, data memory, and a CPU register file. On-chip features include UART, timers, DMA, up to 40 I/O lines. Some versions include a synchronous/asynchronous serial channel. Features fast interrupt response with 37 interrupt sources. The Z8671 has Tiny Basic in ROM. The Super-8 is just that, a super version of the Z8 with more of everything. There seem to be quite a few new members of the zilog Z8 family arriving recently, including chips such as the Z86C95 which contains a fairly "normal" Z8 but with lots of registers (not the normal 128, but 236), and an internal 16 bit harvard architecture DSP with two data memory systems and one program memory system, and with a 24 bit accumulator. The DSP unit has its memory systems accessible as additional banks of Z8 registers (the exact mechanism is very poorly explained in the documentation!) so the Z8 can be used to write the data and code for the DSP into the DSP's storage and then start the DSP running, etc. There are the usual Z8 peripherals plus A/D and D/A (single channel, accessible by the Z8 and DSP CPUs). Zilog has also recently come out with some new OTP parts: osc part# PDIP EPROM RAM I/O type freq --------------------------------------------------------------- Z86E04 18 pin 1K 124 bytes 14 pins xtal,LC, 8MHz cer res,ext Z86E08 18 pin 2K 124 bytes 14 pins xtal,LC, 12MHz cer res,ext Z86E30 28 pin 4K 237 bytes 24 pins xtal,LC,RC, 12MHz cer res,ext Z86E31 28 pin 2K 124 bytes 24 pins xtal,LC,RC, 8MHz cer res,ext All parts come with real configurable RAM stack and interrupt systems, two fully programmable timers with interrupts, ROM protect, low-EMI modes, two analog comparator inputs with interrupt capability, low-power standby modes (as low as 1 uA) and 45 easy instruction set. There are no separate chip versions to do each of the oscillator types, one chip does them all. HD64180 (Hitachi) A powerful microcontroller with full Z80 functionality plus: extended memory management, two DMA channels, synchronous and asynchronous communications channels, timers, and interrupt controller. Some versions of this chip also include EPROM, RAM, and PIO (programmable input/output). It runs Z80 code in fewer clock cycles than the Z80 and adds in hardware multiply and a few other instructions. Available in versions that run up to 18MHz. TMS370 (Texas Instruments) It is similar to the 8051 in having 256 registers, A and B accumulators, stack in the register page, etc. It also has a host of onboard support devices, some members have all of them while others have a subset, the peripherals include: RAM, ROM (mask, OTP, or EEPROM), 2 timers (configurable as timers/ counters/comparators/PWM output), watchdog timer, SCI (syncronous serial port), SPI (asynchronous serial port), A/D (8 bit, 8 channel), interrupts. Instruction set is mostly 8 bit with some 16 bit support. Has several addressing modes, 8x8 multiply, 16/8 divide. Clock speeds are up to 20MHz which gives 5MHz for buss access and instruction cycles. Pins mostly TTL compatible (except clock and reset). Packages include: 28,40 DIP 28 CLCC 28,44,68 PLCC 40,64 SDIP A developers/proto board is available. It is a multi layer PCB about 12"x7" with RS-232 serial I/O, and monitor as well as access to all processor pins on a patch and proto area. Support software includes IBM-PC monitor & loader, cross assembler (absolute only). A pure serial TTY monitor is also supported. Sole power requirement is +5v. Priced is about $500 or so. A relocating assembler and linker, and a C compiler are also available. 1802 (RCA) This is a real old-timer. The 1802 is the successor to the 1801 (2 chip set) which was the first microprocessor implemented in CMOS. Both products were called microprocessors by RCA, not microcontrollers. However, since the 1801 was implemented in CMOS and therefore had low power requirements, it was often used in microcontroller applications. The 1802, with its higher level of integration and ease of use, could actually be considered a true microcontroller. The 1802 is radiation hard and used in a lot of deep space and satellite applications. The 1802 has a fairly clean instruction set, a bunch of general-purpose registers (more like a Z80 than an 8051 in that regard), and separate data and I/O address spaces. MuP21 (Forth chip) The MuP21 was designed by Chuck Moore, the inventor of Forth. With the MuP21, Forth can compile into machine code and still be Forth, because the machine code IS Forth. The MuP21 freaks out at 100 MIPS while consuming only 50 milliwatts. Not only that, the chip includes a video generator, has only about 7000 transistors (that's right, 7000 and not 7,000,000), and costs about $20. The assembler on this chip is a sort of dialect of Forth, as the CPU is modeled after the Forth virtual machine. MuP21 is a MINIMAL Forth engine. In fact MuP21 was designed to run OKAD (Chuck Moore's VLSI CAD softare), and OKAD was designed to run on MuP21. OKAD was run on a 486 to design MuP21, and MuP21 was designed to have just enough hardware to run OKAD about ten times as fast as a 486 on a very cheap chip (the MuP21). That's the reason for the MuP21's on-chip video generator coprocessor. The CPU programs the video generator and then just manipulates the video buffer. It is composite video out, so it only needs one pin. MuP21 is only a 40 pin chip. MuP21 chips, boards, software, manuals, and spec sheets are available from: Offete Enterprises 1306 South B Street, San Mateo CA 94402 (415) 574-8250 Email: tingch@ccmail.apldbio.com tingch@perkin-elmer.com. F21 (Next generation Forth chip) F21 will be bigger (10k vs 7k transistors for the MuP21!) but since it is going to implemented with a smaller geometry (.8 micron vs 1.2) it will still be extremely small and low power, and low cost. Although the specs on this chip aren't final yet, expected performance is in the range of 250 MIPS!!. It will have multiple analog processors and a very high speed serial network coprocessor on chip. F21 will also support a wider range of memory chips and have more I/O processors. Designed for cheap consumer multimedia and parallel processing, the F21 is planned for release some time in 1995. For more information on this project, contact: Jeff Fox <jfox@netcom.com>. 6) GETTING STARTED WITH MICROCONTROLLERS In order to get started with microcontrollers, several factors need to be considered. - cost - convenience - availability of development tools - intended use The hardware described in this section is readily available, affordable, and is easy to find software for. <Inclusion or exclusion of a product in this section doesn't have any real significance. I've tried to give a good cross-section of devices and manufacturers - I'm open for suggestions.> 6.1) Evaluation Kits/Boards Many manufacturers offer assembled evaluation kits or boards which usually allow you to use a PC as a host development system. Among some of the more popular evaluations kits/boards are: Parallax Basic Stamp This is a small single-board controller that runs BASIC, and costs only $39. A SIP version for only $29 is also available. THE 256 byte EEPROM can hold a program of up to about 100 instructions. The BASIC Stamp Programming Package is a complete development package for only $99. Parallax, Inc., 3805 Atherton Rd. 102, Rocklin, CA 95765 (916)624-8333 Fax: (916)624-8003 BBS: (916)624-7101 email: info@parallaxinc.com Motorola EVBU, EVB, EVM, EVS A series of very popular evaluation/development systems based on the 68hc11. Comes complete with the BUFFALO monitor and varying types of development software. Commonly used for university courses. Motorola 68705 starter kit Motorola supplies a complete development system, -- software, hardware, simulator, emulator, manuals, etc for just $100. Dallas Semiconductor DS5000TK The DS5000TK allows evaluation of any DS5000 series device in any existing application without circuit changes. The included DS5000T plugs into the supplied serial interface pod which provides a connection to a host PC. A target cable connects the pod to the target system. Programs can be downloaded directly to the chip (no EPROM programming!) using the built-in serial loader. (With Dunfield's Development System, you end up with a cheap "pseudo-ice". Dunfield also has a circuit if you want to build a similar device.) Philips/CEIBO DS750 For $100 (from Philips, from CEIBO the price is $250), you get a "pseudo-ice" for testing your code in-circuit. Based on the low-end Philips 87c75x parts. Allows source-code debugging in assembler (included), C, and PL/M, with an interface similar to that of Borland's Turbo Debugger. Very popular with students and consultants for experimenting with 80c51 code. Includes a VERY NICE book which describes the theory of operation of the board itself, and includes a good number of experiments that you can try for yourself. Philips sold nearly 10,000 of these boards in the USA (and 5000 in Europe without even advertising). American Educational Systems AES-51, AES-11, AES-88 If you'd like to start learning about microcontrollers, but the thought of finding all the parts and then building one scares you, take a look at the line of boards available from American Educational Systems. This might be the easiest way to get started. For less than $300, you get a complete and professionally designed and packaged educational tool. AES has three boards: AES-51 (8051), AES-11 (68hc11), and AES-88 (8088). All three boards are built along the same lines and include RAM, ROM, LCD display, keypad, A/D, serial ports, digital I/O ports, and logic probe. Also included is a full bookshelf of documentation. These boards are ridiculously easy to use and program - you can get started experimenting and designing right away. This is a perfect system for students and hobbyists. Even professionals will find this system useful as a prototyping tool and test bed. Highly recommended. For more information, contact: American Educational Systems 970 West 17th St. Santa Ana, CA 92706 USA (800)730-3232 or (714)550-8094 Fax: (714)550-9941 6.2) Easy chips to use In addition, several chips provide a similar capability if you are willing to spend a bit of time wiring up a simple circuit. A few chips worth looking at are: Motorola MC68HC11A8P1 Contains Motorola's BUFFALO monitor which has the same functionality as the one on Motorola's evaluation boards. A working system can be built with this chip and a Maxim MAX-232. You can talk to it with a PC or Mac over a 3-wire RS232 connection. It is easy to load and run anything you want in the on-board RAM and EEPROM. You can even use subprograms in the BUFFALO monitor after getting a listing from Motorola's BBS or ftp site. This BBS/ftp site also has freeware assemblers to make a complete development environment cheaply and quickly. Intel 8052AH-BASIC This popular chip with hobbyists is another easy way to get started. You can download high level code from your host. The disadvantages are that you can't get away from a multi-chip solution, the code is noticeably slow, you have to buy an MCS BASIC manual, you are detached from the inner workings, there aren't many on-chip goodies like A/D, and you can forget about running off of a battery. Dallas Semiconductor DS5000/DS2250 These are well suited even for electronics ignoramuses (ignorami?) such as myself. All you need to add is a crystal and two capacitors to end up with a working system. These chips come complete with non-volatile RAM in the form of static RAM (at least 8K) backed up with a lithium battery. Everything is saved - program, data, and bugs ;-). MicroChip PIC '5x series With only 33 instructions, this chip is definitely easy to use! Using Parallax's assembler, the instruction set is ** MUCH ** less intimidating than MicroChip's opcodes! These chips simply need power, ground, and 1 of 4 different timing circuits. Doesn't get much easier than that! With I/O pins that are beefy (25mA per pin sink, 20mA per pin source) and drive both high and low, interfacing is super easy. It's great to hook LEDs and such directly to output pins with only a resister in-line! 6.3) Software (Cheap and easy) Well, it's finally here. A free C compiler for the 8051. Featured in Dr. Dobb's August 1997 issue, Andy Yuen's Retargetable Concurrent Small C (RCSC) is based on James E. Hendrix' lengendary Small C. A previous iteration of RCSC, Concurrent Small C was introduced in the August 1996 issue of Dr. Dobbs. With the release of this compiler, Andy Yuen is very likely to become a folk hero. So, why are you still reading this? The FAQ will wait! First download a copy of RCSC. You can get it from: http://www.ddj.com or ftp://ftp.mv.com/pub/ddj. Then go out and find a copy of Dr. Dobb's August 1997 issue. You'll still need to purchase either James E. Hendrix's "A Small C Compiler" (ISBN 0-13-814724-8) or the Dr. Dobb's Small C Compiler Resource CD. This of course means that the free C compiler isn't totally free, but then again, what is? A couple free versions of C exist for the 68hc11. One is based on Small C and another on the Gnu C package. Neither package is known for ease of use or reliability. However, you might find that one of these packages fits your needs. You can search for free software for development, but you often get what you pay for. What is sorely lacking in freeware is technical support. Several packages are available that provide complete development environments for some of the more popular microcontrollers. If you want to be productive right away, think about investing $100 or so - it'll be well worth the price! I've been playing with the Dunfield Development System lately (on the 8051), and it's really quite nice. I've also heard many good things about it from others. It includes a near ANSI-C compiler, run-time library with source, assembler, ROM debugger, integrated development environment, monitor with source, utilities, and other extras. Although not freeware, the low price ($100), the features, all of the extra goodies, and the good reviews make this a package worth looking at. Also, if you're interested in working on more than one family of microcontroller, Dunfield supports a wide range. This means only needing to learn one system, instead of many. The following chips are supported: 6805, 6809, 68hc11, 68hc16, 8051/52, 8080/85, 8086, and 8096. A package including a simulator and a resident monitor debugger are also available for the 8051 for $50. Dunfield Development Systems P.O. Box 31044, Nepean, Ontario K2B 8S8 Canada (613)256-5820 Fax: (613)256-5821 Email: ddunfield@bix.com A decent C compiler for the 68hc11 comes from ImageCraft. This package, which runs under DOS and OS/2, includes a near ANSI C compiler, assembler, linker, librarian, ANSI C functions and headers, and 90 page manual. The current release is version 1.02 of their compiler. The price is just $40. Initial feedback on this compiler seems promising. The pre-release versions are already in use by many of you, and will still be available as freeware. ImageCraft P.O. Box 64226, Sunnyvale, CA 94086-9991 (Richard Man) imagecft@netcom.com Another low priced ($100) C compiler comes from Micro Computer Control. Cross compilers running under DOS are available for the 8051 and the Z8 (including Super-8). This package includes a C compiler, assembler, linker, librarian, and extensive printed documentation. A simulator/source code debugger is available for an additional $79.95. Micro Computer Control Corporation PO Box 275, 17 Model Ave., Hopewell, NJ 08525 (609)466-1751 Fax: (609)466-4116 BBS: (609)466-4117 Email: 73062.3336@compuserve.com C isn't the only development system available (yeah, I know that's hard to believe) - good solid Basic and Forth development systems are also available. Refer to the appropriate FAQ for the microcontroller that you are using for more information on free and commercial development systems. If the Microchip PIC is your game, then check out the Parallax tools (available on their ftp and web sites). All Parallax software is available free of charge to all takers! This includes PSIM (a PIC simulator), PASM (an assembler for '5x parts), and PASMX (an assembler for 'xx parts). These are the full commercial versions, not hobbled in any way! 7) MICROCONTROLLER PROGRAMMING LANGUAGES Just a bit of an introduction for the beginner. 7.1) Machine/Assembly language Machine language is the program representation as the microcontroller understands it. It is not easy for humans to read and is a common cause of migraine headaches. Assembly language is a human-readable form of machine language which makes it much easier for us flesh and bone types to deal with. Each assembly language statement corresponds to one machine language statement (not counting macros). An assembly/machine language program is fast and small. This is because you are in complete charge of what goes into the program. Of course, if you write a slow, large, stupid program, then it will run slowly, be too big, and be stupid. Assembly language (assembler) can't correct stupidity - although sometimes I wish it could ;-). If you are starting out learning about microcontrollers, it would be worth your while first learning assembler. By programming in assembler, you master the underlying architecture of the chip, which is important if you intend to do anything significant with your microcontroller. 7.2) Interpreters An interpreter is a high level language translator that is closer to natural language. The interpreter itself is a program that sits resident in the microcontroller. It executes a program by reading each language statement one at a time and then doing what the statement says to do. The two most popular interpreters for microcontrollers are BASIC and FORTH. BASIC's popularity is due to its simplicity, readability, and of course just about everyone has at least played with BASIC at one time or another. One common compaint about [interpreted] BASIC is that it is slow. Often this can be solved by using a different technique for performing the desired task. Other times it is just the price paid for using an interpreter. FORTH has a very loyal following due to its speed (approaching that of assembler language) and its incremental approach to building a system from reusable parts. Many FORTH systems come with a host system which turns your desktop computer into a development system. FORTH can be quite difficult to write in (if you have no experience with it) and is probably even harder to read. However, it is a very useful and productive language for control systems and robotics, and can be mastered in time. JVM - Java(TM) Virtual Machine - was added lately to the list of interpreters, after the invention of the language and concepts by Sun Microsystems. Java was adopted enthusiastically by programmers all over the world and has finally found its way into the embedded environment. Java provides a new and revolutionary concept, geared towards the use of portable software applications which can be dynamically downloaded over a network, rather than kept on the local disk or in the local memory of a specific computer. This way, the client computer does not need to keep all the applications, since they can be dynamically downloaded from the server whenever required. Another Java main feature is its Operating-System independent capability. Java is also a language. The Java language is a new object-oriented programming language, also developed by Sun Microsystems. In its very own architecture it is particularly suited to the development of Java's portable application pieces of software, called applets. The nicest thing about developing a system with an interpreter is that you can build your program interactively. You first write a small piece of code and then you can try it out immediately to see how it works. When the results are satisfactory, you can then add additional components until the final product is achieved. 7.3) Compilers A compiler is a high level language translator that combines the programming ease of an interpreter with greater speed. This is accomplished by translating the program (on a host machine such as a desktop PC) directly into machine language. The machine language program is then burned onto an EPROM or downloaded directly to the microcontroller. The microcontroller then executes the translated program directly, without having to interpret first. The most popular microcontroller compilers are C and BASIC. PL/M, from Intel, also has some popular support due to that company's extensive use of that language. Modula-2 has a loyal following due to its efficient code and high development productivity. Ada has many adherents among those designing on the larger chips (16 bits and above). Due to both its popularity and its slow speed, it was only logical that BASIC would appear as a compiled language. A few companies supply a BASIC compiler for several of the more popular microcontrollers. Execution speed is drastically increased over interpreted BASIC since the microcontroller is freed from the task of interpreting the statements as the program runs. While interpreted Forth approaches (and sometimes surpasses) the speed of many compilers, compiled Forth screams along. Today there are many high performance optimizing native code Forth compilers, and there are also lots of very cheap or free public domain Forths. Some of them like Tom Almy's ForthCMP produces optimized native code with less overhead and better performance than just about anything else out there. Of course it still has compactness and more elegant factoring of functionality than in most languages. C is now the language of choice for the entire universe. C is used on computers from the tiny microcontroller up to the largest Cray supercomputer. Although a C program can be a bit tedious at times to read (due to the terse programming style followed by many C programmers), it is a powerful and flexible development tool. Although a high level language, it also gives the developer access to the underlying machine. There are several very good and cheap C compilers available for the more popular microcontrollers. It is widely used, available, supported, and produces fairly efficient code (fast and compact). 7.4) Fuzzy Logic and Neural Networks Fuzzy Logic and neural networks are two design methods that are coming into favor in embedded systems. The two methods are very different from each other, from conception to implementation. However, the advantages and disadvantages of the two can complement each other. The advantage of neural networks is that it is possible to design them without completely understanding the underlying logical rules by which they operate. The neural network designer applies a set of inputs to the network and "trains" it to produce the required output. The inputs must represent the behavior of the system that is being programmed, and the outputs should match the desired result within some margin of error. If the network's output does not agree with the desired result, the structure of the neural network is altered until it does. After training it is assumed that the network will also produce the desired output, or something close to it, when it is presented with new and unknown data. In contrast, a fuzzy-logic system can be precisely described. Before a fuzzy control system is designed, its desired logical operation must be analyzed and translated into fuzzy-logic rules. This is the step where neural networks technology can be helpful to the fuzzy-logic designer. The designer can first train a software neural network to produce the desired output from a given set of inputs and outputs and then use a software tool to extract the underlying rules from the neural network. The extracted rules are translated into fuzzy-logic rules. Fuzzy logic is not a complete design solution. It supplements rather than replaces traditional event control and PID (proportional, integral, and derivate) control techniques. Fuzzy logic relies on grade of membership and artifical intelligence techniques. It works best when it is applied to non-linear systems with many inputs that cannot be easily expressed in either mathematical equations used for PID control or IF-THEN statements used for event control. In an effort to change fuzzy logic from a "buzzword" (as it is in most parts of the world) to a well established design method (as it is in Japan), most manufacturers of microcontrollers have introduced fuzzy logic software. Most software generates code for specific microcontrollers, while other generates C code which can be compiled for any microcontroller. 8) DEVELOPMENT TOOLS Having a programming language is usually not enough to develop a program for a microcontroller. Some way of debugging your program is needed. I am only too painfully aware of this fact. 8.1) Simulators A simulator runs your microcontroller program on a host machine (such as your PC). You can step through the code to see exactly what is happening as the program runs. Contents of registers or variables can be altered to change the way the program runs. Eliminates (or at least delays) the erase/burn/program EPROM cycle common in microcontroller program development. You can work out ideas or learn about microcontrollers by experimenting with small code fragments and watching on the screen what happens. A simulator can't support real interrupts or devices, and usually runs much slower than the real device the program is intended for. Some manufacturers have a cross between a software simulator and the hardware emulator - a hardware simulator. This is a piece of equipment that plugs into your target, and the pins will toggle and react like they should - just MUCH slower. Cost of a device like this is only about $100. Two such boards by National Semiconductor and Philips are detailed in section 6.2. 8.2) Resident Debuggers A resident debugger runs your program on the microcontroller itself, while showing the progress on your host machine (such as a PC). Has many of the same advantages as simulator above, with the additional benefit of seeing how the program runs on the real target machine. A resident debugger needs to "steal" some resources from the target machine, including: a communications port to communicate with the host, an interrupt to handle single stepping, and a certain amount of memory for the resident part (on the target) of the debugger. 8.3) Emulators If you've got the money, this is the equipment you want to develop your system with (yeah, that's right, a preposition at the end of a sentence!). A [usually] expensive piece of hardware that even for the cheaper versions will run you at least $700. An emulator is a sophisticated device that pretends that it is the microprocessor itself, while at the same time capturing information. It provides full and total control over your target, while at the same time not requiring any resources from the target. The emulator can either be a stand alone device with its own display, or it can be interface to a PC. 8.4) Java on Embedded Systems <Thanks to Marius Gafen of NSI in Israel for the following discussion of Java> This is a short discussion about the technology of Java (TM) implementation on Embedded Systems and the issues involved. This technology implementation can bring to the embedded systems world the benefits of Java, enabling the development of extensible, portable and downloadable applications, which dramatically reduce development costs and provide fast response to ever changing market demands, while keeping all existing advantages. Java - Write once, run everywhere ... Java provides a new and revolutionary concept, developed by Sun Microsystems and geared towards the use of portable software applications which can be dynamically downloaded over a Network, rather than kept on the local disk or in the local memory of a specific computer. This way, the client computer does not need to keep all the applications, since they can be dynamically downloaded from the server whenever required. After the applications are done, they can be either kept on the computer or discarded - as required. Of course, these applications do not need to exist when the computer is built or purchased - they, or their later versions, can be developed and added at a later stage. Java enables dynamic interaction, where the user receives immediate feedback. Java provides Operating-System independent capability. Java provides all these features by allowing the execution of code that can be distributed across the network in a portable, robust, secure and high-performance environment. Java - The Language The Java language is a new object-oriented programming language, also developed by Sun Microsystems. In it's very own architecture it is particularly suited to the development of Java's portable application pieces of software, called applets. These are applications which are dynamically downloaded over the network and executed on the Java-Enabled client computer, normally equipped for this purpose with a Java-Enabled Web Browser. Java - The Components The Java system compiles Java applets into Byte Code. Once compiled, the Java Byte Code is placed in a file ready to be downloaded through the Network to the client computer that requests it. A Java-Enabled Web Browser includes a component called a Java Virtual Machine (or JVM, for short). This component is responsible for actually running the Java Byte Code and it isolates the Java code from the specifics of the underlying hardware and operating system. Consequently, Java applets are developed once but they can run, unchanged, on any client computer with a Java Enabled Web Browser, regardless of the specific platform. Implementation of Java in Embedded Systems The use of Java in an embedded environment presents unique challenges, due to the fundamental differences between an embedded system and a general-purpose computer or work-station. These differences should be thoroughly understood in order to better appreciate the implications associated with implementing Java to a particular application domain. a. An embedded system usually lacks secondary storage (e.g. a hard disk) making it difficult to keep a library of application code and to load a particular routine upon demand. Therefore, the size of the application is limited to the size of the existing memory device (such as ROM or Flash). b. In most cases, an embedded system lacks direct user interface such as a monitor. Rather, it communicates with the operator (if at all) through some specialized devices or through a front-end station which is connected to the embedded application via a specialized bus or network. c. The lack of a file-system and traditional user interface devices has a special significance for Java-based applications which rely heavily on the presence of these components. Often, an embedded application has limited resources such as memory and CPU bandwidth. Consequently, the scheduling and sharing of these resources become one of the major design challenges when developing such an application. Particularly, in Real-Time applications, the performance requirements and the constraints on resources lead to lean and fine-tuned scheduling disciplines in order to meet the system's performance requirements. d. Typically, an embedded system is very specialized; it is tightly integrated with the surrounding environment and has demanding requirements for robustness. Since the protection mechanisms (such as address-space boundary protection) that are usually provided by a typical operating system are not available in such an environment, the mechanism of introducing new software into the application should be tightly controlled. This fact has special significance in the context of Java where the programming paradigm is based on dynamic downloading of applets from various sources. Java was designed (and initially implemented) to run on UNIX workstations. It relies on many services that are available on such a system (such as files, processes, Internet naming services) which do not exist in a typical embedded system. Some of these do not make sense in such an environment (for example, a network device might have an IP-address, but it does not necessarily have a domain name). Implementation Architectures In order to execute Java code on an embedded system, several key components must be developed or ported to this system. These components have to be tailored to the specific hardware, to the kernel (if one exists) and to some extent to the C compiler being used (since part of the JVM and its interface layers are implemented in C). The two main possible approaches are: a. Developing a dedicated Java-compatible system, exactly fitted to the embedded environment. b. Porting Sun's original Java to the embedded environment. The first approach has the advantage of ending with a product which is originally designed to the embedded environment, including all the constraints of this special environment. The second approach has the advantage of compatibility to the de-facto standard which has been already adopted by the industry. Since Java is a live language and environment, driven by both the industry needs and the rapid technology changes, this factor is considered to be of tremendous importance. More architectural concepts For achieving appropriate compatibility with all Java existing and future intrinsics, the only possible approach of porting Java is based on Sun's JDK (Java Development Kit) sources as distributed from Sun. These sources were analyzed and checked against the requirements of the embedded environment, before being carefully restructured. The final result is retargetable software which lends itself to be easily ported to each unique combination of hardware - kernel - C compiler. This software runs on a variety of Real-Time Operating Systems and provides a Virtual Machine environment for the execution of Java byte code. Special design considerations enable it to coexist with other applications, which are running on the same platform, either Real-Time or Non-Real Time, while complying with the constraints imposed by the Real-Time Operating System and the application tasking architecture. JVM Encapsulation As mentioned previously, the ideal technique would be the one which enables the embedded Java software to run on top of any commercial Real-Time kernel or be adapted to any application-specific executive. This capability is accomplished by having a well-defined API that encapsulates the services that the JVM needs from the underlying system. The Java language supports parallelism in the form of threads (light-weight tasking). It includes methods for thread management, synchronization and communication. There are two approaches for mapping the Java threads to the parallel entities of the underlying kernel (typically, they are called tasks): a. Mapping each Java thread to a kernel task and utilizing the kernel services to schedule these threads and synchronize between them. b. Dedicating one kernel task to run the JVM and then have the Java threads be implemented internally by the Java run-time support system. Again, there are tradeoffs to be considered when choosing the appropriate model. In the first model, the services of the Real-Time kernel are used directly for managing the Java threads and can, in some situations, perform better. In addition, Java threads can interact directly with other tasks in the system. However, this approach requires that the overall system be fully tested each time a new Java thread is introduced or a change to the Java code is performed. In the second approach, the JVM acts also as an intermediate monitor, which internally manages the Java threads and ensures that the Java code as a whole performs accurately within its resource boundary. It therefore ensures that in any circumstances the JVM does not exceed the amount of system resources allocated to the Java application. The practical meaning of this implementation approach is that once the JVM has been fully tested in a particular environment, the different applets can be downloaded and executed with no need to re-test. 8.5) Good Stereo System This is the most important tool for the microcontroller developer, or for any computer system developer for that matter. Don't expect to get anywhere unless you have the proper music playing in the background(?) at the proper volume. I find that I do my best work with the Rolling Stones (especially Goats Head Soup) or Clapton (especially early stuff like Cream - Disraeli Gears is a killer album!). The volume must be set to cause excrutiating pain to be most effective. Trust me on this ;-). Tom Mornini of Parallax reports: "Johnny Cash also has a certain effectiveness, as well as the Beatles, Aerosmith, and Rush! 60's rock and British invasion bands in particular seem to have a particularly productive effect." This would be an interesting topic for an in-depth study. Particularly intriguing, is if certain types of music work better with specific [families of] processors. Another question in need of study would be if it's really true that the smaller the chip (in bits), the louder the music needs to be. 9) FINDING OUT MORE ABOUT MICROCONTROLLERS If you are interested in learning more about microcontrollers, there are many fine sources of information. You have your choice of printed media (books, periodicals, informative graffiti) or interactive (right here on the Internet, or BBSs). 9.1) Books 8-bit Microcontroller Instruction Set Performance - Digitial Systems Consulting / June 1994 - compares Motorola's M68HC05, Intel's 80x51, Microchip's PIC16C5x, and National's COP8 - lit number 630008 - (800)272-9959 call this number for copies The 16 bit 8096: Programming, Interfacing, Applications - Ron Katz and Howard Boyet - Microprocessor Training Inc 14 East 8th Street, New York, NY 10003 212-473-4947 - Library of Congress Catalog card number: 85-61954 - According to William Chernoff: "The book is pretty good - mostly software examples. The one hardware thing I looked closely at was wrong - a schematic error. Oh well." The 68hc11 Microcontroller - Joseph D. Greenfield (at R.I.T.) - Saunders College Publishing, (Harcourt Brace Jovanovich) - 1992 - ISBN 0-03-051588-2 - A number of the sections make use of the Buffalo monitor. This could be useful if you are using the Motorola Trainer EVB. The 8051 Family of Microcontrollers -Richard H. Barnett -Prentice-Hall, 1995 (yeah, that's right, 1995!) -ISBN 0-02-306281-9 8051 Interfacing and Applications - Applied Logic Engineering 13008 93rd Place North, Maple Grove, MN 55369 - (612)494-3704 The 8051 Microcontroller - I. Scott MacKenzie - Prentice Hall - 2nd edition, 1995 - ISBN 0-02-373660-7 - includes schematics for a single-board computer, assembly-language source code for a monitor program, and interfaces to a keypad, LEDs, and loudspeaker The 8051 Microcontroller - James W. Stewart - Regents/Prentice-Hall, 1993 - $27.50, 273 pages - includes many interfacing examples (switches, solenoids, relays, shaft encoders, displays, motors, and A/D converters) and a chapter on top-down design method The 8051 Microcontroller: Architecture, Programming and Applications - Kenneth J. Ayala - 241 pages, soft cover - 5.25" diskette with assembler and simulator - ISBN 0-314-77278-2, Dewey 004.165-dc20 - West Publishing Company P.O. Box 64526, St. Paul, MN 55164 (800)328-9352 - see review in next section The Art of Programming Embedded Systems - Jack G. Ganssle - 1992, 279pp, $55.00 - ISBN: 0-12-274880-0 - CONTENTS: Introduction, Initial Considerations. Elegant Structures. Designs for Debugging. Design for Test. Memory Management. Approximations. Interrupt Mamangement. Real-Time Operating Systems. Signal Sampling and Smoothing. A Final Perspective. Appendixes: Magazines, File Format. Serial Communications. Bibliography. Index. Assembly Language Programming (for the MCS-51 family) - F. A. Lyn - L. S. Electronic Systems Design Basic-52 Programmer's Guide - Systronix, Inc. (they also sell a Basic compiler) - address above Beginner's Guide - Suncoast Technologies A Beginners Guide to the Microchip PIC - Nigel Gardner - Character Press, Ltd. (UK) - ISBN 1 899013 00 8 - software (on floppy) and hardware guide, debugging techniques - suitably titled, for those with no previous microcontroller experience - 19.95 UK Pounds The PIC Source Book: - assembly language source code on diskette - $39 - Scott Edwards Electronics 964 Cactus Wren Lane, Sierra Vista, AZ 85635 (602)459-4802 Fax: (602)459-0623 72037.2612@compuserve.com C and the 8051 - Thomas W. Schultz - Prentice Hall - ISBN 0-13-753815-4 Data Acquisition and Process Control with the M68HC11 Microcontroller - Frederick Driscoll, Robert Coughlin, Robert Villanucci of Wentworth Institute of Technology. - Macmillan Publishing Company - 1994 - ISBN 0-02-33055-X - Several Chapters on the 68HC11, instructions, and EVB; chapters on interfacing Analog and Digital signals to the 68HC11; example applications of interfaces to temperature, load cell, pressure and thermocouple sensors. - a good companion to Motorola's "pink" books Data book / Handbook / Users' Guide - Advanced Micro Devices - Dallas (User's guide for the DS5000) - Intel - Siemens Design with Microcontrollers - John B. Peatman - ISBN 0-07-049238-7 - This book is on a more advanced level. Uses both the 68hc11 and Intel 8096 as example systems. - Used for a very popular course on microcontroller design at Georgia Tech. Embedded Controller Forth for the 8051 Family - Academic Press - William H. Payne - uses a Forth development system available on the Internet Embedded Controllers Databook 1992 Edition - National Semiconductor Corporation - literature number: 400049 - (800)272-9959 call this number for for copies Embedded Systems Programming in C and Assembler - John Forrest Brown - Van Nostrand Reinhold, 1994 - 304 pages, $49.95 - ISBN 0-442-01817-7 - covers Motorola and Intel processors - includes diskette with code from the book - book review in Dr. Dobb's Journal, November 1994, page 121 Experimenter's guide - Rigel Corporation Introduction to Microcontroller Design, Based on the 8051 family of Processors - Business Data Computers P.O. Box 1549, Chester, CA 96020 Mc68hc11 An Introduction - Han-Way Huang - Software and Hardware Interfacing, Applications using the EVB from Motorola. - West Publishing Company - ISBN 0-314-06735-3 M68hc11 Reference Manual - Motorola - literature reference M68HC11RM/AD - This document is the "bible" of the 6811 and is a must-have for any serious 6811 programmer. MC68hc811E2 Programming Reference Guide - Motorola - literature reference M68HC811E2RG - A pocket-sized guide to the version of the 6811 used on the Mini Board The Microcontroller Idea Book - Jan Axelson (of Microcomputer Journal fame) - features the 8052-BASIC microcontroller - hands-on guide with complete plans (schematics, design theory, program listings, construction details, etc) - explains how to use sensors, relays, displays, clock/calendars, keypads, wireless links, and more - 1994, 273 pages, $31.95 + shipping - Lakeview Research, 2209 Winnebago St., Madison, WI 53704 (608)241-5824 Internet: 71163.3555@compuserve.com - contact the author at janaxel@aol.com Microcomputer Engineering - Gene H. Miller - Prentice Hall, Englewood Cliffs, NJ 07632 - 1993 - ISBN 0-13-584475-4 - Explains the basics. Many clear and concise assembly language example programs. - Written to be used with the Motorola Trainer (EVB). Microcontroller Technology, The 68hc11 - Peter Spasov - Prentice Hall - ISBN 0-13-583568-2 Microcontrollers: Architecture, Implementation, and Programming - Kenneth Hintz and Daniel Tabak - McGraw-Hill Inc. 1992 - ISBN 0-07-028977-8 Microprocessor 1995 - Jack Quinn, Micrologic Research - Integrated Circuit Engineering Corporation 15022 North 75th St., Scottsdale, AZ 85260-2476 (602)998-9780 Fax: (602)9481925 - comprehensive study of the microprocessor industry and market, current status, trends, and developments - $1495 - Microprocessor 1996 due out in November PIC 16Cxx Development Tools instructions manuals - Parallax, Inc. - Instruction manual for the Parallax PIC assemblers - Instruction manual for the Parallax Software Simulator - Instruction manual for the Parallax PIC programmer hardware - Details the Parallax PIC instruction set PIC 16Cxx Applications Handbook - Parallax, Inc. - Contains condensed data sheets for '5x, '64, '71, and '84 controllers - Contains 14 application notes showing circuits and code for common projects using the PIC series of microcontrollers. Easy PIC'n, A Beginner's Guide to Using PIC16/17 Microcontrollers" - ISBN 0-9654l62-0-8 - intended to ease the beginner toward understanding and application of the PIC16/17 line of microcontrollers from microchip Technology Inc. For the hobbyist or engineer for self study or as a text for a college engineering course in the application of microcontrollers. - examples of assembly language programs - in-depth coverage of program writing using flow charts - the approach is hands-on with lots of examples, all of which may be demonstrated using a very simple demo board (a project) described in the beginning of the book - For more information, contact the author: David Benson, Author (Easy PIC'n) Owner, Square 1 Electronics squareone@zapcom.net (707)279-8881 Fax: (707)279-8883 Posix.4: Programming for the Real World - Bill O. Gallmeister - O'Reilly and Associates, 1995 - ISBN 1-56592-074-0 - Part I of the book describes the Posix standard (what it is, what it isn't, and what it's for), and explains the principles of real time programming (tasking, messages, scheduling, I/O, and performance) and why Unix isn't fit for real-time programming. Part II is a reference on the Posix functions and header files. Part III contains much of the code for the exercises in the book. Programmer's Guide to the 1802 - Tom Swan - Hayden Book Company, Inc., 1981 - ISBN 0-8104-5183-2 - good introduction to assembly language progamming and an thorough tutorial on the 1802 Programming Microcontrollers in C - Ted Van Sickle - HighText Publications, 1994 - 394 pages, $29.95 - ISBN 1-878707-14-0 - thorough tutorial on C programming, covers aspects of C programming specific to embedded systems - covers the Motorola line of microcontrollers (small to large) - book review in Dr. Dobb's Journal, November 1994, page 121 The Real-Time Kernel - Jean Labrosse - R&D Publications, Inc. Suite 200 1601 W 23rd St., Lawrence, KS 66046 - (913)841-1631 Fax: (913)841-2624 - Based on the article "A Portable Real Time Kernel in C" in Embedded Systems Programming (Part 1: vol 5 no 5 May 1992, Part 2: vol 5 no 6 June 1992) - originally written for the Intel 186 but ported to HC11 source code for UCOS11 Single- and Multiple-Chip Microcomputer Interfacing - G.J. Lipovski - Copyright 1988 - 478 pages - ISBN 0-13-810557-X (Prentice-Hall Edition) ISBN 0-13-810573-1 (Motorola Edition) - Based around the 68HC11 it covers both hardware and software at undergraduate level, but the emphasis is on interfacing. - Chapter titles: 1 Microcomputer Architecture 2 Programming Microprocessors 3 Bus Hardware and Signals 4 Parallel and Serial I/O 5 Interrupts and Alternatives 6 Analog Interfacing 7 Counters and Timers 8 Communications Systems 9 Storage and Display Systems Single- and Multiple- Chip Microcomputer Interfacing (Lab Manual) - Peter Song and G. Jack Lipovski - Prentice-Hall, 1988 - ISBN 0-13-811605-9 - Support for the above book. Examples based around the Motorola EVB and the BUFFALO monitor or the EVBU (or 3-chip micro) and PC-Bug11. User Manual for the CDP1802 COSMAC Microprocessor - RCA, 1977 - contains useful hardware and software techniques Using the M68HC11 Microcontroller: A Guide to Interfacing and Programming, 1/e - John C. Skroder, Texas A & M, Institute of Electronics - Prentice Hall, 1996, $77.00 - Copyright 1997, 627 pp. cloth - ISBN 0-13-120676-1 - Table of Contents 1. Introduction to the M68HC11. 2. M68HC11 Resets and Interrupts. 3. M68HC11 Parallel I/O. 4. Parallel I/O Using the Simple-Strobed and Full-Handshake Modes. 5. The M68HC11 Serial Communications Interface (SCI). 6. The M68HC11 Serial Peripheral Interface (SPI). 7. M68HC11 Free-Running Counter and Input Captures. 8. M68HC11 Output Compare Functions. 9. M68HC11 Forced Output Compares, Real-Time Interrupts and Pulse Accumulator. 10. M68HC11 Analog-to-Digital Conversions and Fuzzy Inference. 11. M68HC11 Expanded-Multiplexed Mode. Appendix A. M68HC11EVB Board. Appendix B. M68HC11EVBU Board. Appendix C. Connecting the EVB/EVBU to External Circuits. Appendix D. AS11 Assembler. Appendix E. M68HC11 Instruction Set. Appendix F. Parts/Equipment Listing. 9.2) Data and Reference Books Motorola - M68hc11 Reference Manual, ref # M68HC11RM/AD this document is the "bible" of the 6811 and is a must-have for any serious 6811 programmer contact Motorola at 800-521-6274 (in the U.S.) to get a free copy of this manual - MC68hc811E2 Programming Reference Guide, ref # M68HC811E2RG a pocket-sized guide to the version of the 6811 used on the Mini Board, "ownership of this handy reference is proof of being a true 6811 nerd" - by Fred Martin National Semiconductor - (800)272-9959 for copies - COP8 Databook, ref # 400007 - COP8 Selection Guide, ref # 630006 - COP8 Designers Information Kit, ref # 6300007-005 contains: - COP8 Databook (1994 Edition) - COP8 Selection Guide (1994 Edition) - Independent 8-bit Instruction Set Analysis - Independently prepared software analysis of National's COP8, Motorola's M68Hc05, Intel's 80X51, and Microchip's PIC16C5X - Utility and Overview Disks - Self-lead overview on COP8, includes electronic selection guide and sample application code - COP8 Utility Disk, Mac ref # 6300000, Windows ref # 630001 typical microcontroller applications and sample code available by ftp nscmicro.national.com in/pub/COP8 - COP8 Overview Disk, Mac ref # 630004, Windows ref # 630005 self-lead COP8 overview, shows product features/benifits and includes a electronic selection guide (2 disks) available by ftp nscmicro.national.com in /pub/COP8 9.3) Periodicals Various magazines and journals (journals seems to be THE popular name for magazines these days) provide articles from time to time on microcontrollers. If you are just starting out learning, pick those magazines that feature construction articles. The Computer Applications Journal (Circuit Cellar Ink) - programming and construction articles - POB 7694, Riverton, NJ 08077-8784 - Fax: (203)872-2204 - Voice orders: (609) 786-0409 - On-line orders (BBS): (203) 871-1988 - Email orders: ken.davidson@circellar.com - $21.95, $31.95 surface Canada and Mexico, $49.95 air all other countries Computer Design - industry announcements and trends - One Technology Park Drive, P.O. Box 990, Westford, MA 01886 - (508)692-0700 The Computer Journal - programming and construction articles, specializing in old computers (S-100, CP/M, TRS-80, Xerox, Adam, etc) - P.O. Box 3900, Citrus Heights, CA 95611-3900 - (800)424-8825 or (916) 722-4970 FAX: (916) 722-7480 - BBS: (916) 722-5799 - WWW: http://www.psyber.com/~tcj - Email: tcj@psyber.com Dave Baldwin: dibald@netcom.com Bill Kibler: kibler@psyber.com - USENET newsgroup alt.tcj Control Engineering - industry outlook on control, instrumentation, and automation systems - Cahners Publishing - Circulation: 8773 S. Ridgeway Blvd., Highlands Ranch, CO 80126-2329 (303)470-4000 - Editorial/Executive Offices: 1350 E. Touhy Ave, P.O. Box 5080, Des Plaines, IL 60017-5080 (708)635-8800 Dr. Dobbs Journal - programming articles, concepts, and designs - 411 Borel Ave., San Mateo, CA 94402 - (415)358-9500 EDN - Cahners Publishing Company 8773 South Ridgeline Blvd., Highlands Ranch, CO 80126-2329 - annual microprocessor and DSP editions - http://www.ednmag.com/ Electronic Engineering Times - industry announcements and trends - 500-B Bi-County Boulevard, Farmingdale, NY 11735 - (516)293-3000 Electronics Now - construction articles - Box 55115, Boulder, CO 80321-5115 - $19.97 one year Elektor Electronics - programming and construction articles - World Wide Subscription Service Ltd Unit 4, Gibbs Reed Farm, Pashley Road Ticehurst TN5 7HE, England - 27 UK pounds or - Old Colony Sound Lab, P.O. Box 243, Peterborough, NH 03458 - Tel. (603) 924-6371, 924-6526 - Fax: (603) 924-9467 - $57 USA and Canada per year Embedded Systems Programming - programming and systems design articles - Miller Freeman Publications - 500 Howard St., San Francisco, CA 94105 - Miller Freeman: (415)905-2200 Embedded Systems Programming phone: (800)829-5537 Forth Dimensions - monthly magazine on Forth - Forth Interest Group, P.O. Box 2154, Oakland, California 94621 - (510)893-6784 Fax: (510)535-1295 - Email: johnhall@aol.com - Forth Interest Group home page: http://taygeta.oc.nps.navy.mil/fig_home.html Inquisitor Magazine - If you're the type that watched Gilligan's Island for its socio-political insights, then you'll love a new 'zine that just crossed my desk - Inquisitor Magazine. It's general philosophy seems to be ... well, it seems to be ... uh, yeah! Technical in nature, bizarre, tongue in cheek, eclectic, electric, did I mention bizarre(?), and lots of fun. Worth looking at if you like the out of the ordinary. The moving force behind this magazine is Daniel Drennan, who seems to have suffered from an overdose of radiation from his computer monitor ;-). - Dan is offering issue 1 of Inquisitor for free except for postage ($1.00 in the United States; $2.00 for Canada and overseas surface mail; and $3.00 for overseas airmail). This issue contains plans, schematics, and troubleshooting tips for putting together a 8052-based microcontroller. If you're thinking of putting together an 8051 system, you might want to check this out. - Planetarium Station, P.O.Box 132 New York, NY 10024-0132 - (212)595-8370 - Email: inquisitor@echonyc.com - $16 per year (4 issues) Microcomputer Journal (formerly Computer Craft) - programming and construction articles - 76 N. Broadway, Hicksville, NY 11801 - $18.95 one year, foreign $23.00, foreign air mail $76.00 Midnight Engineering - 1700 Washington Ave., Rocky Road, CO 81067 - (719)254-4553 MW Media - Product Directories - Motorola Microcontroller Tools Directory ('94 edition out in 3 weeks) - Motorola 68K Source ('94 edition available now) - Intel Development Tools Handbook ('95 edition just beginning) (survey of commercial development tools for the 8051, 8096, and 80186 lines of Intel microprocessors) - Embedded Intel 386 Directory (released in Aug '94) - Intel 486/Pentium directory (forthcoming in '95) - 8051 Product Directory ('94 edition out in 4 weeks) (survey of various 8051 products) - Hitachi Microcontroller Development Tools Directory (out in '95) - AMD FusionE86 Directory (out in '95) (186,386,486) - AMD 29K Directory (pending in '95) - Low Power Product Directory (out in '95) (3.3. volts and lower) - DSP Directory (released in May '94) - Multimedia CD (hopefully out in '95) - These documents could very well be a "must" if you're into serious development using any of these chips. If you are "just" a hobbyist, see how the "other half" lives. - FREE to qualified developers - MW Media - Fairmont Plaza, 50 W. San Fernando, #675, San Jose, CA 95113 - (408)288-4721 (408)286-4200 FAX: (408)288-4728 Nuts & Volts Magazine - A National Publication for the Buying and Selling of Electronic Equipment - 430 Princeland Court, Corona, CA 91719 - Mailed third class, USA only: $17.00 one year $31.00 two years - Mailed first class, one year only: $34.00-USA $35.00-Canada/Mexico - Foreign/Air Mail - $70.00; Foreign/Surface - $39.00 - (800)783-4624 - Email: 74262.3664@Compuserve.com 9.4) USENET newsgroups Various newsgroups frequently have discussions or information on various microcontrollers. Among some of the more useful (especially the first 3 newsgroups): comp.robotics Microcontrollers figure heavily in robotics projects. You will find a lot of information about the subject in this newsgroup. Even if you aren't building a robot, check this newsgroup out. Lots of 68hc11 activity, too. comp.arch.embedded (great!) This is a great newsgroup. Well targeted discussions on aspects of embedded systems and microcontrollers. sci.electronics (lots of traffic, but good) alt.comp.hardware.homebuilt (too much nonsense on PCs) Some good places to find [mostly technical] discussions on microcontroller use and implementation. Most of the participants are crazy about "rolling their own", and are eager to share their knowledge. These groups aren't well focused, and many subjects that aren't relevant to embedded control are covered here. comp.realtime Since embedded systems (controllers/processors) are almost always used in real time applications, this group could prove to be useful. Occasional discussions about various microcontroller topics. comp.os.qnx QNX is the leading realtime OS for PCs in terms of market share. It is used in high-end embedded systems (16 and 32 bit); set-top boxes, automotive industry, banking, telecomms, etc. comp.sys.m68k The full line of Motorola 68000 microprocessors is discussed in this newsgroup, including the very powerful and advanced embedded processors and microcontrollers based on this family. comp.sys.6809 This newsgroup covers an old-time favorite, the 6809 microprocessor, which is commonly used for control applications. Motorola 8 bit microprocessors and microcontrollers (6805, 6811, etc.) are also discussed in this newsgroup. comp.sys.intel Mostly trends and development are discussed in this newsgroup. From time to time you will find a discussion on some technical problem or feature. This newsgroup is usually fairly useless. For a while the participants spent most of their time whining about the Pentium bug. Now they're all moaning about Microsoft, PowerPCs, and everything else BUT Intel parts. I propose changing the name of this group to alt.crybabies.boo.hoo.hoo. comp.lang.misc Sometimes questions or discussions on different microcontroller topics pop up here. I guess it's the ".misc" that attracts these questions. comp.ai.fuzzy Fuzzy logic is rapidly becoming an increasingly important aspect of [embedded] control systems. This group might very well become an important forum for those involved in developing control systems. comp.dsp Discussions on Digital Signal Processsing comp.sys.ti Texas Instruments products discussed here sci.engr.control This forum is for the discussion of control and embedded systems. sci.engr.semiconductors 9.5) Internet sources of information on specific microcontrollers If you are interested in finding sources of information on a specific microcontroller, check out the really fine FAQs ;-) that have been compiled for the more popular microcontrollers. Subject: PIC microcontrollers Newsgroups: <no longer posted to newsgroups> Web page: http://digiserve.com/takdesign Maintainer: Tom Kellett Email: Tom@takdsign.demon.co.uk Subject: 8051 microcontrollers Newsgroups: comp.sys.intel comp.realtime comp.robotics comp.lang.forth sci.electronics Archive: rtfm.mit.edu : <plus all mirror sites> /pub/usenet/comp.answers/microcontroller-faq/8051 /pub/usenet/sci.answers/microcontroller-faq/8051 /pub/usenet/news.answers/microcontroller-faq/8051 Maintainer: Russ Hersch Email: russ@shani.net Subject: 68hc11 microcontrollers Newsgroups: comp.realtime comp.robotics sci.electronics Archive: rtfm.mit.edu : <plus all mirror sites> /pub/usenet/comp.answers/microcontroller-faq/68hc11 /pub/usenet/sci.answers/microcontroller-faq/68hc11 /pub/usenet/news.answers/microcontroller-faq/68hc11 Maintainer: Robert Boys - Ontario, Canada Email: rboys@best.com Russ Hersch (maintainer emeritus :-) Subject: Motorola 68K microprocessor line Newsgroups: comp.sys.m68k Archive: ftp.ee.ualberta.ca : pub/motorola/general ftp.luth.se : /pub/misc/motorola/faq file name of archive is m68kfaq?.zip (? is version) Comments: - also includes information on the 683xxx and 68hc16 - without a doubt, one of the finest FAQs ever written (well, of course Bob paid me to say this ;-) Maintainer: Robert Boys - Ontario, Canada Email: rboys@best.com Subject: ST6 microcontroller FAQ Newsgroups: sci.electronics comp.arch.embedded comp.robotics comp.realtime Maintainer: Emilio Caggiano - caggiano@vm.csata.it Jerry van Kampen - ersicjer@er.ele.tue.nl Leonhard Schneider - ubie@rz.uni-karlsruhe.de Several other FAQs have been compiled that address various aspects of microcontroller design and implementation. Subject: I2C protocol Newsgroups: sci.electronics alt.hardware.homebuilt comp.robotics comp.protocols.misc. Comments: The I2C bus is a simple 2 wire serial interface developed by Philips. A number of 8051 variants as well as several peripherals include I2C support. Maintainer: Vincent Himpe Email: Vincent.Himpe@ping.be Subject: Robotics Newsgroups: comp.robotics Maintainer: Kevin Dowling (412)268-8830 Email: nivek@ri.cmu.edu Smail: Carnegie Mellon University The Robotics Institute Pittsburgh, PA 15213 Subject: Electronics Newsgroups: sci.electronics Comments: There are a number of FAQs available in this newsgroup on various subjects. Among some of the subjects covered are: LCDs, stepper motors, suppliers, etc. Subject: Real-time Newsgroups: comp.realtime, comp.answers, news.answers Archive: rtfm.mit.edu : pub/usenet/comp.realtime Maintainer: Mark Linimon Lonesome Dove Computing Services Roanoke, Virginia Email: linimon@nominil.lonesome.com. Subject: Neural Networks Newsgroups: comp.ai.neural-nets,comp.answers,news.answers Archive: rtfm.mit.edu : pub/usenet/neural-net-faq Maintainer: Lutz Prechelt Email: prechelt@ira.uka.de Subject: Fuzzy Logic Newsgroups: comp.ai.fuzzy,comp.answers,news.answers Archive: rtfm.mit.edu : pub/usenet/fuzzy-logic/ Maintainer: Mark Kantrowitz Email: mkant+@cs.cmu.edu Subject: alt.comp.hardware.homebuilt FAQ Newsgroups: alt.comp.hardware.homebuilt Comments: This file contains frequently asked questions (FAQ) and general information pertaining to the newsgroup alt.comp.hardware.homebuilt. Maintainer: Mark Sokos (msokos1@gl.umbc.edu) 10) MICROCONTROLLER FREE SOFTWARE SOURCES This section includes descriptions and references to free microcontroller software. FTP sites and BBSs contain many quality packages and code samples for free. For heavy duty use, you might prefer the many commercial packages that are available. With the public domain (or free) stuff, you're usually on your own. The commercial packages usually provide extensive documentation and support. If you are looking for commercial software for the 8051, 68hc11, or PIC, then check out the FAQs on these microcontrollers for details on what is available. 10.1) FTP sites The following is a list of the anonymous ftp sites that have source code and programming languages for various microcontrollers. There are many others that are not listed here that contains bits and pieces. Usually you can find them using Archie and searching for variations on the name of the microntroller you are looking for. ftp.pppl.gov (formerly lyman.pppl.gov) - this is a great source of 8051 stuff /pub/8051 /pub/incoming - check this out for new untested/unsorted items ftp.mcc.ac.uk - this is a new 8051 ftp site ftp.intel.com - good source of stuff the MCS-51 and MCS-96 families /pub/mcs51 - various development tools and sample code for the MCS-51 family /pub/mcs96 - various development tools and sample code for the MCS-96 family nctuccca.edu.tw - mirror of ftp.intel.com /vendors/Intel freeware.aus.sps.mot.com (Motorola) - the ftp site version of the freeware BBS - lots of free software for the HC05, HC08, HC11, HC16, 680x0, 683xx, and PowerPC - also see the Web pages in the next section nscmicro.national.com - the authoratative source for COP8 infomation /pub/COP8 - various develepment tools and sample code for the COP8 family including most application notes ftp.zilker.net - /pub/philips - Philips "mini ftp site" set up by Phil Wood of Philips - lots of 8051 code and programming tools from their BBS Philips-archive@InetBSystems.us.com - send Email message with the word "help" in the subject line to learn how to access the archive ftp.ee.ualberta.ca - Circuit Cookbook - HUGE archive of all sorts of stuff on the 68hc11 (lots of other good stuff too!) - you'll have fun mucking around this ftp site, there's piles of stuff here /pub/cookbook /pub/motorola /pub/motorola/68hc11 /pub/motorola/mcu11 cherupakha.media.mit.edu (cher.media.mit.edu) - HUMONGOUS archive of all sorts of stuff on the 68hc11 including the 6.270 robotics project, Mini Board, F1 board, and more (lots of other good stuff too!) - you'll lose yourself rooting around this ftp site, there's piles of stuff here (assemblers, tools, C compilers, plans and schematics, and many other items) /pub/projects - tools, docs, schematics, etc. for the MIT 6.270 robotics project using a 68hc11-based development system /pub/6811 - software, schematics, etc. for the 68hc11-based F1 board /pub/incoming - various unsorted or new items /pub/miniboard - software, docs, schematics, etc. for the 3"x2", 68hc11-based Mini Board controller ftp.funet.fi (nic.funet.fi) - this is a good source for various microcontrollers /pub/microprocs/ (subdirectories include: 1802, 6805, 8048, 8051, 8096, PIC and many other microprocessors) ftp.sics.se - many assemblers, utilities, and application notes for the PIC - Microchip BBS mirror - ftp site of Memec Scandinavia, Microchip's Swedish agent. /pub/mchipsoft ernie.uvic.ca - files provided by local Motorola representative /pub (subdirectories include: ibm, dsp96k, dsp56100, dsp56k, dsptools, develop, mac, mcu302, mcu332, mcu11, pgmr, mcu16, mcu, market, qa, general, m68k, evm, dsp) wpi.wpi.edu - basic stamp information - PIC "C" compiler /stamp ftp.std.com /vendors/microchip/ ftp.luth.se /pub/misc/microchip - PIC information /pub/misc/microchip/stamp/mirror - mirror of wpi.wpi.edu /pub/languages/assembler - various freeware assemblers ti.com read the 00readme file first or you'll be lost asterix.inescn.pt - FORTH archive /pub/forth hpcsos.col.hp.com /mirrors/.hpib0/forth/8051 (mirror of asterix Forth archive) /mirrors/.hpib0/forth/eForth /misc/ns32k/beowulf ftp.netcom.com /pub/imagecft - prerelease version of ImageCraft C for 68hc11 info@circellar.com - Email (not ftp) - send Email to get information file on services available - all Circuit Cellar INK and BYTE related files available ftp.ultranet.com /biz/mchip - PIC information - also see the Web page: http://www.ultranet.com/biz/mchip ftp.mrc-bbc.ox.ac.uk /pub/microchip ftp.oak.oakland.edu - has information and software for a wide range of microprocessors and microcontrollers ftp.uni-erlangen.de - information on PIC /mounts/epix/public/pub/Multimedia/VideoCrypt/ microcontroller/microchip.bbs ftp.armory.com (Steve Walz) - /pub/user/rstevew/8051 - /pub/user/rstevew/TB8051 - /pub/user/rstevew/incoming ftp.cygnus.com (Jeff Fox) - source of information and software on the MuP21 Forth microcontroller /pub/forth - MUP21FTP.ZIP includes a software simulator for the MuP21 and and the upcoming F21. also see the Web page: http://www.dnai.com/~jfox ftp.best.com /pub/cera ftp.netcom.com /pub/ce/cera - embedded systems FTP archive ftp.parallaxinc.com /pub - ftp site of Parallax "Cool PIC development tools & the BASIC Stamp" ftp.std.com - Minds-Online ftp site /customers2/nonprofits/minds-online - Chock full of compilers, assemblers, code, articles, fuzzy logic, and much more. evans.ee.adfa.oz.au /mirrors/tms340 - support for Texas Instruments parts ftp.ti.com /mirrors/tms320bbs - mirror of the contents of Texas Instruments BBS ftp://iglou.com/members/ITU - Microchip PIC and embedded systems ftp://ieee.cas.uc.edu - electronics archive 10.2) Web pages Advanced Micro Devices, Embedded Processor Division home page - http://www.amd.com/html/products/EPD/EPD.html - covers both the 29K and E86 embedded processor lines Ada language pages - http://sw-eng.falls-church.va.us/AdaIC/ - http://www.adahome.com/ AM Research, the Embedded Control Experts - http://www.amresearch.com Automation and Process Control - http://www.ba-karlsruhe.de/automation/home.html Bo Eriksson's web page (mostly in Swedish :-( - http://194.52.151.18/elektronik/internettips/index.html - info on tools from IAR, plus interesting links - info on H8-series from Hitachi Brian Brown's 8051 web page - http://www.cit.ac.nz/smac/cbt/hwsys/i8051/default.htm - contains Brian Brown's 8051 course - lots of other good stuff Cera Research web pages - Electronic Engineers' Toolbox (home page) http://www.cera2.com/ebox.htm - MCU/MPU resources http://www.cera2.com/micro.htm - Navi-GATOR (embedded dev. tools and chip-specific) http://www.cera2.com/gator.htm Chip Directory and Chip Manufacturers (Jaap van Ganswijk) - http://www.hitex.com/chipdir (USA, California) - http://www.civil.mtu.edu/chipdir (USA, Michigan) - http://www.leg.ufrj.br/chipdir (Brasil) - http://www.xs4all.nl/~ganswijk/chipdir (The Netherlands) - http://bbs.cc.uniud.it/chipdir (Italy) Chipmakers web page (Gary Creager) - http://www.scruznet.com/~gcreager/hello5.htm - well over 200 semiconductor manufacturers web pages Circuit Cellar Ink - http://www.circellar.com Dallas Semiconductor - http://www.dalsemi.com Diamond Chip - http://www.dchip.com - information on their ST62T25 BASIC chip - Stefan Ward, Diamond Chip Tel +27 (0)12 803-6287 Fax +27 (0)12 803-4350 BBS +27 (0)12 803-5683 Electronic Laboratory of the DAEC Department of Meudon - http://formper1.obspm.fr - electronics, embedded systems, FPGA, microncontrollers in astronomy projects Embedded Systems Information (Cera Research) - http://www.cera.com Forth Interest Group home page - http://taygeta.oc.nps.navy.mil/fig_home.html French Forth web site - http://ourworld.compuserve.com/homepages/mp7 maintained by Marc Petremann: 17, allee de la Noiseraie F - 93160 NOISY LE GRAND Email: 100647.3306@compuserve.com - http://ourworld.compuserve.com/homepages/bioforth maintained by Gerard SOULA Gernsback Web page (Electronics Now, Popular Electronics) - http://www.gernsback.com - current issue information, recent article related files, FTP site, subscription information Gregory Pugh's homepage - http://sleepy.anest.ufl.edu/~glp/8051.html High Tech Horizon - http://www.hth.com - This web page is in Swedish, but the files are available to all in the "Hardware Hackers Filelibrary" at the bottom of the Web-page. - High Tech Horizon, Asbogatan 29 C, S-262 51 Angelholm, SWEDEN +46 431 41 00 88 Fax: +46 431 41 00 88 Email: info@hth.com Hitachi - http://www.hitachi-eu.com/hel/ecg/ ITU Technologies (ITUTec@aol.com) - Microchip PIC and embedded systems - http://www.iglou.com/ITU Ken Tindell's CAN web pag - http://www.nrtt.demon.co.uk/can.html - Source code to drive the Intel 82527 CAN controller is available: just send e-mail to info@nrtt.demon.co.uk, with "Request Intel 82527 drivers" (without the quotes) in the subject line. MCU Survey - http://bip.golana.pub.ro/mcu/survey Microchip PIC - http://www.ultranet.com/biz/mchip Motorola's semiconductor WWW page - http://motserv.indirect.com - on-line searchable Master Selection Guide and OEM Price Book - 'MFax' service to request all kinds of data sheets - a bunch of other cool stuff Motorola's microcontroller WWW page - http://freeware.aus.sps.mot.com/index.html - the WWW version of the freeware BBS - lots of free software for the HC05, HC08, HC11, HC16, 680x0, 683xx, and PowerPC MuP21 Forth microcontroller - http://www.dnai.com/~jfox - information and software on the MuP21 Forth uC Parallax Inc. web page - http://www.parallaxinc.com - "Cool PIC development tools & the BASIC Stamp" Peter H. Anderson's web site - http://www.access.digex.net/~pha - nice site, lots of PIC stuff and interfacing plans - Peter H. Anderson Dept of Electrical Engineering Morgan State University POLIS web site - POLIS offers an integrated interactive environment for specification, co-simulation, formal verification, and synthesis of embedded systems implemented as a mix of hardware and software components. - http://www-cad.eecs.berkeley.edu/Respep/Research/hsc/abstract.html Most of the information about POLIS, including pointers to source and object code (for various CPUs and OSes) is available at this WEB site - If you are interested, but do not have WEB access, contact them at: polis@ic.eecs.berkeley.edu. QNX realtime website - http://www.qnx.com Scrumpel 68hc11 web page - http://www.stack.urc.tue.nl/~hcc6811 Texas Instruments - http://www.ti.com/sc/docs/micro/home.htm Zorin - http://www.eskimo.com/~zchris - 68hc11 information and support for their line of boards 10.3) BBSs The following BBSs have 8051 information: Circuit Cellar, Inc. - contains code from their magazine articles and from the original Circuit Cellar articles in Byte magazine, also contains many other interesting items - The BBS is mentioned in the masthead of each issue (on the table of contents page). Excerpts from the BBS appear in Ken Davidson's ConnecTime column in every issue with a description of how to access the system at the end of every column. - (203)871-1988 - Voice: (203)875-2751 - Fax: (203)872-2204 Dunfield Development Systems - support for their Micro-C C compiler and development tools - includes a lot of nice goodies - (613) 256-6289 ED Teck. Pubs BBS - run by Fred Eady who writes for hobbyist magazines - good source of information on the PIC - (407)454-3198 Electronics Now - contains code from their magazine articles - (516)293-2283 Intel American Marketing Applications Support Bulletin Board System - 16 lines, hi-speed modems (14.4K) - Lots of useful info and files (including design examples) - Full ANSI-BBS with color is recommended, but support for just about all terminal types is provided - 916-356-3600 (24 hours) Auto config: 1200 thru 14.4K Baud 8 data bits, no parity, 1 stop Iota Systems, Inc. - Support for their line of hardware and software products - (702)831-4732 Jens Holm's electronics BBS: - one of a number of BBSs that are networked over most of the industrial part of Europe - +45-86-510356 (Denmark) - distributes all shareware and freeware software which relates to electronics - system administrator - Jens Holm jholm@bjarke.nrg.dtu.dk or Jens.holm@asgaard.dk Don Lekei BBS - support for the PIC line of microcontrollers - (604)597-3479 (Canada) Massilia Underground BBS (Marseille, France) - +33-91794120 - fidonet 2:323/25 - not a commercial BBS - microcontroller related stuff (assemblers, debuggers, boards, etc), some 8051 stuff - everything coming in is tested Microchip BBS - support for the PIC line of microcontrollers - Contact by dialing the same number you would use to get to Compuserve at 19200,n,8,1, except that you press +<CR> at the (garbage) prompt, followed by MCHIPBBS as the host (instead of CIS). Micro Computer Control Corporation - (609)466-4117 Motorola (Austin Texas) BBS - terrific, has piles of stuff, only some of which is on bode.ee.ualberta.ca - (512) 891-3733 (Austin, Texas) - V.32 9600 Baud modems w/ MNP-5 - 8 Data Bits, No Parity, 1 Stop Bit. Other Motorola BBSs: - Munich, Germany: 49-89-92103-111 (2400 baud) - Stuttgart, Germany: 49-7031-275496 (19200 baud) - San Diego, California: (619) 279-3907 - Toronto, Ontario, Canada: (416) 497-8989 National Semiconductor COP8 BBS - (800)672-6427 - worldwide telnet to nscmicro.national.com Protel (Microchip PIC software support) - (408)243-0125 Parallax Inc. - (916)624-7101 Philips Semiconductor (parent company of Signetics) - support for: standard logic, programmable logic, in-car electronics (planned), 8 and 16 bit microcontrollers, I2C software, third party software, discrete semiconductors, cross assemblers (general), RF (planned) - PHIBBS is located in the Netherlands: +31-40-721102 - maximum 14400 baud / V42bis - 24 hours a day available - Help desk: +31-40-722749 (9.00 AM - 16.00 PM CET) Philips Semiconductors (Signetics) - support for their 8051 variants - contains many good source code items - partially mirrored on ftp.pppl.gov and nic.funet.fi - (800)451-6644 or (408)991-2406 Texas Instruments microcontroller BBS - (713)274-3700 10.4) Mailing Lists 68hc11 - for information, send empty message to listserv@hipp.etsu.edu - to join, send the message "subscribe mc68hc11 your_real_name" to listserv@hipp.etsu.edu Basic Stamp - to join, send the message "subscribe stamp-list" to majordomo@cybernetics.net GCC compilers for embedded systems - to join, send the message "subscribe crossgcc <your address>" to majordomo@first.gmd.de - for those who are building a cross gcc compiler for an embedded processor/system Imagecraft C - to join, send the message "subscribe icc11-list" to listserv@netcom.com Minds-Online - One mailing list is for announcing significant postings on the Minds-Online ftp site. - Another MODERATED mailing list will carry messages from real engineers who are working on designs slated for volume production. "No tire-kickers, no students, no academics, no sleazy something-for-nothing ripoff artists, no hobbyists, and no totally lost people will be able to post e-mail." (Uh, it looks like that sort of leaves out yours truly, I certainly belong in several, if not most, of those categories). - to join, send the message "subscribe" to the email address: minds-online@world.std.com Mini Board and 6.270 board (68hc11) - send a message containing the word "help" for directions to listserv@oberon.com - mailing list address: robot-board@oberon.com - maintainer: gkulosa@oberon.com Parallel Performance Group (PPG) - series of monthly newletters on high-tech software topics - for information send any e-mail to info@ppgsoft.com Philips Newsletter - send Email with "subscribe" in the subject field to Philips-News@InetBSystems.us.com - news, views, and articles (contributions welcome) Philips Developers Forum - send an Email message with the word "subscribe" in the subject to Philips-forum-request@InetBSystems.us.com - technical discussions between engineers and developers PIC - to subscribe, send email to listserv@mitvma.mit.edu - send the message "SUB PICLIST" for standard subscription - send the message "SUB PICDIGEST" to receive digested mailings - list address is: PIC@mitvma.mit.edu 11) SOURCES FOR PARTS Major manufacturers and distributors are the main (and most expensive) source for acquiring microcontroller parts. A good number of firms have surplus bargains on microcontrollers and other parts you might need for your projects. Among some of the better ones: All Electronics - http://www.allcorp.com - lots of great surplus items - nice catalog available in PDF Alltronics - http://www.alltronics.com - good selection of interesting surplus items - large selection of standard chips and components - latest advertisements available in PDF - update pages from catalog available in PDF BG Micro - http://www.bgmicro.com - large selection of standard chips and components - much of their catalog available in PDF Debco Electronics - http://www.debcom.com - piles of chips, parts, components, ham gear, computer stuff - Electronics Experimentors Journals (highly recommended!) Herbach and Rademan - http://www.herbach.com - great catalog - LOTS of stuff for robotics projects Mendelson Electronics - http://www.meci.com - on-line ordering possible, but IMHO their web site is difficult to navigate Timeline - http://www.timeline.com - well-known and reliable source for surplus LCD displays - interesting surplus bargains __________________________________________________________ I disclaim everything. The contents of this article might be totally inaccurate, inappropriate, misguided, or otherwise perverse - except for my name (hopefully I got that right). Copyright (c) 1997 by Russ Hersch, all rights reserved. This FAQ may be posted to any USENET newsgroup, on-line service, or BBS as long as it is posted in its entirety and includes this copyright statement. This FAQ may not be distributed for financial gain. This FAQ may not be included in commercial collections or compilations without express permission from the author. ----------------------------------- Russ Hersch - russ@shani.net