1. CS 478: Microcontroller Systems University of Wisconsin-Eau Claire Dan Ernst CE 478 Microcontroller Systems http://www.cs.uwec.edu/~ernstdj/courses/ce478 Prof. Dan Ernst Spring 2011

2. CS 478: Microcontroller Systems University of Wisconsin-Eau Claire Dan Ernst Welcome Class overview –Policies etc. –What are embedded systems? –Why are they interesting? –Why are they needed? Note: There is no required textbook for this class! Office hours: Wednesday: 9 – 11 am Friday: 1 – 3 pm or by appointment

3. CS 478: Microcontroller Systems University of Wisconsin-Eau Claire Dan Ernst Labs and Equipment Fridays are Lab days in P 122. (not 171!) – There may be some exceptions (watch your e-mail!) In labs you will sometimes be in groups of 2 Equipment needs to stay in the lab area.

4. CS 478: Microcontroller Systems University of Wisconsin-Eau Claire Dan Ernst Grading* Item Weight ====== ========= Labs/Homeworks30% Exams (2) 30% (15% midterm; 15% final) Project 30% Quizzes10%

5. CS 478: Microcontroller Systems University of Wisconsin-Eau Claire Dan Ernst Final Project Final Project will involve constructing a “polished” digital system –Implement the hardware and software involved in your design –Ideas and examples of projects are/will be posted on the class website Project will involve multiple phases –Proposal –Implementation –Presentation/Documentation

6. CS 478: Microcontroller Systems University of Wisconsin-Eau Claire Dan Ernst What we will cover* PowerPC architecture and assembly language Bus protocols and interfacing –Including P6, PPC, and maybe others Digital design review Common I/O devices –Timers, A/D converters, serial I/O, etc. Interrupts –I/O devices demanding attention Direct Memory Access (DMA): –I/O devices talk directly to memory Memory technologies: SRAM, DRAM, Flash etc Analog to digital and back again. Error correction and other “special” topics.

7. CS 478: Microcontroller Systems University of Wisconsin-Eau Claire Dan Ernst Administrivia P122 access : You’re welcome to work in P122 on 478-related projects anytime, except Weds. 2 – 4 pm and Tues. 3:30 – 5:30 pm ( CS 278 lab) If you can avoid it, don’t leave the boards out – there will be plenty of cabinet space, and other classes (CS 278) need to use the space. You will receive a key to the cabinets on the first lab day. Please don’t distribute the access code, or let in extra people! http://www.cs.uwec.edu/comdistro

8. CS 478: Microcontroller Systems University of Wisconsin-Eau Claire Dan Ernst

9. CS 478: Microcontroller Systems University of Wisconsin-Eau Claire Dan Ernst General Purpose Computers Microcomputers are computers based on microprocessors –General purpose microcomputers PC’s, Macs, etc. –Generally require a large amount of support circuitry Memory, communications, I/O, keyboard,display...

10. CS 478: Microcontroller Systems University of Wisconsin-Eau Claire Dan Ernst Inside a General Purpose Computer CPU RAM ROM PCI Bus Bridge Address Bus Data Bus PCI Bus Clock, Reset circuitry Control Bus Real-time Clock Disk Controller Disk Interface Video Memory Video Display Controller Serial Interface Parallel Interface... Keyboard/ Mouse Controller

11. CS 478: Microcontroller Systems University of Wisconsin-Eau Claire Dan Ernst Does One Size Fit All? Advantages of a general-purpose computer –Flexible - can run lots of programs and interface with lots of devices –Expandable - can be updated with new hardware –Cost-effective - the cost of adding a new program is small –Economy of scale - millions are being produced… Disadvantages –Must be a “super” system, capable of running any program –High price –Relatively large, short battery life

12. CS 478: Microcontroller Systems University of Wisconsin-Eau Claire Dan Ernst Embedded Systems Embedded Systems are small, special-purpose computer systems Rocket guidance systems Toaster control systems Handheld electronics Toys –Only the necessary parts are included Cheaper, smaller –Simpler --> more reliable?

13. CS 478: Microcontroller Systems University of Wisconsin-Eau Claire Dan Ernst Needs of Typical Embedded Systems Consider the following embedded systems: –Programmable thermostat –Blood Glucose Meter –iPod Touch ™ –Automobile System Controller Single-purpose Small Inexpensive Reduced computation needs (most of the time) Special interfaces Lightweight (often hand held)

14. CS 478: Microcontroller Systems University of Wisconsin-Eau Claire Dan Ernst So… You don't need a traditional user interface to decide which programs should be running You don't need to dynamically load programs into your devices You don't need to waste time waiting for the O/S to load –if one is needed, then it doesn't have baggage that make it slow to load You don't need to load programs or data from a slow disk drive - most information needed will be in fast ROM

15. CS 478: Microcontroller Systems University of Wisconsin-Eau Claire Dan Ernst Why PCs Aren’t Practical for Everything What does it take to build a blood glucose meter using a typical PC microprocessor? 1 Intel/AMD/other CPU Dynamic RAM, controller ROM (one or two chips) for program Real-time clock LCD panel Serial interface ports, drivers A/D Converter Random support chips (five or six chips) This is going to take around 5+ chips, use > 100 W, and cost > $400.

16. CS 478: Microcontroller Systems University of Wisconsin-Eau Claire Dan Ernst ASICs: The Other End of the Spectrum Since consumer electronics are made to do one thing, we should just be able to hardwire a solution! Construct an ASIC (Application-Specific Integrated Circuit) –Custom chip that does a single thing, but does it VERY well! –Very little need for software support Downside: making a custom mask will cost you a fortune –Lots of engineering design time –At least $10,000 up front to make a mask –$$$ to reserve time in the fab (or build your own fab)

17. CS 478: Microcontroller Systems University of Wisconsin-Eau Claire Dan Ernst FPGA – a middle solution? Could use an Field-Programmable Gate Array (FPGA) –(a la 278) Advantages: –Programmable –Much cheaper than ASICs (at least in small quantities) Disadvantages: –Not as intuitive as software –Still not super-cheap –Take up a lot of space/power relative to the capability they bring

18. CS 478: Microcontroller Systems University of Wisconsin-Eau Claire Dan Ernst The Spectrum of Hardware/Software Solutions

19. CS 478: Microcontroller Systems University of Wisconsin-Eau Claire Dan Ernst Why Consumer Electronics make Money A Microcontroller is a small CPU with support devices built into the chip –Small CPU –Small ROM –RAM, EEPROM –Parallel ports –RS232 ports –A/D Converter –Timer Typically, a microcontroller uses little power and costs $0.50 to $100.00

20. CS 478: Microcontroller Systems University of Wisconsin-Eau Claire Dan Ernst A Generic Microcontroller Small CPU Core 8-32 Bits 2-40 MHz Flash EEROM 2KB – 256KB RAM 256B – 64KB GPIO ADC 8-14 Bits Timer 16-32 Bit RS232/ USB I2C/SPI Memory Bus 16-24 Bits

21. CS 478: Microcontroller Systems University of Wisconsin-Eau Claire Dan Ernst Embedded Systems Definition: Dedicated to controlling a specific real-time device or function Self-starting, not requiring human intervention to begin. The user cannot tell if the system is controlled by a microprocessor or by dedicated hardware (or magic!) Self-contained, with the operating program in some kind of non-volatile memory

22. CS 478: Microcontroller Systems University of Wisconsin-Eau Claire Dan Ernst How are things controlled? Switches –Switches can be used to switch things on or off e.g. lights can be on or off –They can also be used to switch between values e.g a heater can be set to a number of values Sensors –Sensors can tell if something is on or off –Sensors can tell you the value of something e.g. temperature Timers –Timers can control the duration of other activities, such as how long a light is on, or the time between ADC samples Analog controllers –Things such as voltage can be set for analog devices such as motors

23. CS 478: Microcontroller Systems University of Wisconsin-Eau Claire Dan Ernst What we will cover* PowerPC architecture and assembly language Bus protocols and interfacing –Including P6, PPC, and maybe others Digital design review Common I/O devices –Timers, A/D converters, serial I/O, etc. Interrupts –I/O devices demanding attention Direct Memory Access (DMA): –I/O devices talk directly to memory Memory technologies: SRAM, DRAM, Flash, etc. Analog to digital and back again. Error correction or other “special” topics