Assembly Microprocessors session 1

1. Assembly Microprocessorssession 1 ing. Ernst E. Mak MSc

2. Programming • Programming is any set of formalized instructions to be executed in a skilful but in a rather slave like fashion. • Programs tend to be sequential in nature • Programs act upon? • computers but also Video recorders, DVD recorders, Television sets, Oven, Home baking Machines, Alarm Clocks etc etc and even: Pets and Humans.

3. Example Human program • Go out of door and turn right • At the end of the street turn left • take 3th crossing to the right • go until the end of the street • turn right • 4th door to the left • output of a Tom-Tom? Human2Human explanation to an address? Instructions to a child to go and fetch milk at the grocery?

4. Another Human2Human program: • Target: to get familiar with the Deeds Assembly environment. • Enter using the Editor: • ORG 0000 ;start at reset-location • jp 100 ;jump to program area • ORG 100 ;continue at program area • ld b,5 ;store 5 into the B-register • add a,b ;add B into the A register • halt ;stop the program • Compile the program, enter the debugger • Observe: registers, memory, program counter, step-key, run, reset and stop/start • Vary: contents of the A register at program start and observe changes in the registers and the flags. • Explain your findings. • Deliver: the program, explanation (max 100 words • What this was? • >>> it’s Problem 1 at section 2 of this course • Think it’s not programming????? • Lets see: it’s a sequential set of instructions • to be executed skilful • unwillingly (?) (are deviations allowed by own initiative?)

5. Levels of Programming • Adult 2 Adult: “pass me the Salt, will you?” • Adult 2 Child: • “Tommy, see the glass container over there? • Yes, the one you point at now, • Could you take it in your hand • And give it to Mammy? • No, no throwing, just give it..........”

6. Human 2 Computer • HUMAN WORLD GAP !!!! • COMPUTERWORLD creative, unreliable, unpredictable, original, complex Exact Predictable Dumb Rigid Simple

7. Interfaces • Human interfaces: • input: eye (images), ear (sounds), hands (sense, feel, locate, probe...)....... • output: mouth (sound), hands (manipulate) • Could you interact to another Human without these interfaces?

8. Interfaces (2) • Input: • keyboard, • mouse, • Microphone • .....etc • Output • Screen, • Printer • Loudspeaker • .....etc • Could you interact to a computer without any of such?

9. Human communication • Requires flexibility, as Humans are never too precise and quite clumsy in expressing themselves. • I’ve got butterflies in my stomach (really??) • I’m dying from curiosity (well???) • This wine has a rich bouquet (define !!) • My neighbour is a pig (name three meanings to this!!) • You little Bastard (would your little nephew really feel offended because of this now??) • Hi Pumpkin!! (how DOES your girlfriend look like?)

10. Interfaces (3) • Any interface in sequential systems will have buffer functionality • BUFFER=memory to temporary store the received information and process it a little later. • QUESTION: do you respond to each word individual or to a sentence or to the intention of your communication partner? where do you store the information at what time?

11. The ANY COMPUTER • Any computer (program processing entity) will quit likely have: • INPUT device • OUTPUT device • MEMORY device • SKILL section (to know what to do with input to produce output) • and something more:..... A TIMER

12. A TIMER????? • How do you know somebody is ready talking (so you can start analyzing his story to be able to answer) • You think YOU are without timer? do not tell this to your HEARTH

13. BASIC COMMANDS • What is the minimal command to have someone to pick up some pencil from the table? • lift pencil • pick up the pencil, please • move your hand to the long laying object, fold thump, index finger and middle finger around it and move your hand up

14. Basic Commands (2) • 1 = shortest, military style (why do they barkshort commands only??) • 2 = polite style • 3 = extensive descriptive into details • QUESTION: analyze what is your position (standing, intelligence, power) towards the receiving party in these communications • you: smart, respected, • the other: drilled limited thinking, equal and child-inexperienced

15. PROGRAMMING HIERARCHY • HUMAN • HIGH ORDER PROGRAMMING ENVIRONMENT • PROGRAMMING LANGUAGE • ASSEMBLY • PROCESOR dumb smart

16. PROGRAM ROUTINE STACKING • Graphical User Interface • Program • Operating Environment (Windows) • DISK Operating System (DOS) • Basic input/output system (BIOS) • Machine code

17. WHAT IS UNDERSTOOD by a Microprocessor • yes vs. no • TRUE vs. FALSE • ONE vs. ZERO • == basic information = BIT • permutations, binary system, • group by 8 bits (By-EIGHT => BYTE) • this could be DATA or program instruction (coded by a number)

18. ELEMENTARY Computer Lay-out MEM data+instructions I/O External CPU

19. Model CPU PC R1 R2 MAR A B IR ALU MDR DECODER SR C ICU TIMER CLOCK

20. Legend to the Microprocessor • MAR = memory address register • MDR = memory data register • PC = program counter • SR = Status Register • A,B,C = registers • R1, R2 = even more registers • ALU = arithmetic and logic unit • IR = instruction register • ICU = internal clock unit

21. Main registers. Alternative registers. Accumulator Registers Interupt register Alternative Registers Memory Refresh Adress Registers Z80 Processor Register Layout I A’ A F F’ R W Z W’ Z’ B C B’ C’ D E D’ E’ Flags 8 bit H L H’ L’ S Sign Z Zero I X - - H Half-Carry I Y - - S P P/V Parity/overfl. P C N Negate C Carry