1. Single Chip Microcontrollers 7765J Mount Druitt College of TAFE Lesson 1

2. © Mike Stacey 2008 Assessment  Practical Test 1: 30%  Practical Test 2: 40%  Theory Test: 30% Assignments  There are 4 assignments which constitute your practical work for this subject  They must be submitted by email by the due date/time  Practical tests are based on the weekly practical exercises you do in class.

3. © Mike Stacey 2008 Assignment submission  Each of the 4 assignments must be submitted by email and should include: Title page – name, subject name, class time and assignment number Flow chart of your program Program listing – with comments. Your program has to be demonstrated to the teacher for verification that it works!

4. © Mike Stacey 2008 Website and subject material  The subject resources include: These PowerPoint slides. They should be downloaded and printed (pdf version) prior to coming to class. Your extra notes which are added to the printed version of the slides. Lesson outline sheet Practical work – assignments All downloadable from www.acay.com.au/~mstacey

5. © Mike Stacey 2008 Topics  Microcontroller characteristics including understanding of data sheets, I/O ports, hardware timers  The AVR studio programming environment  Interfacing to and scanning a keypad  EEPROM loading  More advanced assembly language programming

6. © Mike Stacey 2008 Timeline

7. © Mike Stacey 2008 Embedded uP Systems  What is an embedded uP system? Special purpose computer system to perform a limited range of functions Limited functionality as opposed to a microprocessor Usually includes hardware, software, mechanical parts Incorporates a microcontroller chip (sometimes even a uP)  Examples Routers, MP3 players, digital watches, traffic lights and larger systems such as process control units, Engine management systems in automobiles, Electronic measurement instruments (such as digital multimeters, frequency synthesisers, and oscilloscopes), Printers, Mobile phones, Televisions, radios, CD players, tape recording equipment, Hearing aids, Security alarm systems, fire alarm systems, and building services systems

8. © Mike Stacey 2008 1. Telephone decoupling electronics (for ADSL). 2. Multicolour LED (displaying network status). 3. Single colour LED (displaying USB status). 4. Main processor, a TNETD7300GDU, a member of Texas Instruments' AR7 product line. 5. JTAG (Joint Test Action Group) test and programming port. 6. RAM, a single ESMT M12L64164A 8 MB chip. 7. Flash memory, obscured by sticker. 8. Power supply regulator. 9. Main power supply fuse. 10. Power connector. 11. Reset button. 12. Quartz crystal. 13. Ethernet port. 14. Ethernet transformer, Delta LF8505. 15. KS8721B Ethernet PHY transmitter receiver. 16. USB port. 17. Telephone (RJ11) port. 18. Telephone connector fuses. Router-modem Assignment 3 due

9. © Mike Stacey 2008 History  The first modern embedded system was the Apollo Guidance Computer at MIT Collected and provided flight information and automatically controlled all of the navigational functions of the Apollo spacecraft First to use integrated circuits, 5600 of them  Single 3 input NOR gates 4 x 16 bit registers Weight 70lbs User interface

10. © Mike Stacey 2008 Apollo Guidance Computer 5600 gates, approx. 4k memory, 16 bit data bus, 16 bit address bus, used AGC assembly language on top of a real time operating system. 34 instructions. Weighs 70lbs.

11. © Mike Stacey 2008 Typical characteristics of an embedded system using a microcontroller  Designed to do some specific task, rather than be a general-purpose computer for multiple tasks  Not always separate but often built into the environment they control  Software for embedded systems called firmware and burnt into flash memory  Limited hardware resources Small or no keyboard Often no monitor Small memory (RAM and flash)  Limited UI - exceptions PDAs etc. Often use LEDs, small character LCDs, buttons

12. © Mike Stacey 2008 Reliability  Often embedded systems must run in harsh environments for long service periods and also may have to recover automatically from error  Hence software is tested more rigorously!

13. © Mike Stacey 2008 Microcontroller systems and microprocessor (uP) systems comparison  Microcontroller (uC) has RAM, ROM, I/O (serial and parallel), buses, clocks  Both are built on the “stored program concept” or Von Neumann machine uC stored program in flash memory uP stores it on disk Both allow “easy” program modification  uC has limited memory, both Ram and ROM so large complex programs are not possible  They are designed to perform a limited and specific range of tasks  uP perform a wide variety of general purpose tasks and can incorporate large complex programs Larger instruction set Larger memory capacity

14. © Mike Stacey 2008

15. STK500 90S8515 RS232 to computer COM port for programming Power 12V LED x 8 connector Port B Switches x 8 connector Careful when connecting cables!!! Power Switch

16. © Mike Stacey 2008 AVR Studio IDE  Obtain this program from me and install it at home.  Also obtain the 90S8535 data sheet and bring it to class each week.  It allows you to program, compile and simulate

17. © Mike Stacey 2008 Example.include "8535def.inc" rjmp RESET ;Reset Handle RESET:.def temp =r16 ; These 4 lines of code just init the ; Stack Pointer to the end of the ; RAM address space ldi temp,low(RAMEND) out SPL,temp ldi temp,high(RAMEND) out SPH,temp INIT_PORTC: ser temp out DDRC, temp LOOP_1: ser temp out PORTC, temp nop clr temp out PORTC, temp nop rjmp LOOP_1 see class demo: eg_lesson1.asm