Download Assembly Microprocessors session 1

Assembly Microprocessors
session 1
ing. Ernst E. Mak MSc
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.
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?
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?)
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..........”
Human 2 Computer
• HUMAN WORLD
creative,
unreliable,
unpredictable,
original,
complex
GAP !!!!
• COMPUTERWORLD
Exact
Predictable
Dumb
Rigid
Simple
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?
Interfaces (2)
• Input:
–
–
–
–
keyboard,
mouse,
Microphone
.....etc
• Output
–
–
–
–
Screen,
Printer
Loudspeaker
.....etc
• Could you interact to a computer without any of such?
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?)
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?
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
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
BASIC COMMANDS
•
What is the minimal command to have
someone to pick up some pencil from the
table?
1. lift pencil
2. pick up the pencil, please
3. move your hand to the long laying object,
fold thump, index finger and middle finger
around it and move your hand up
Basic Commands (2)
• 1 = shortest, military style (why do they bark
short 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
smart
PROGRAMMING HIERARCHY
• HUMAN
• HIGH ORDER PROGRAMMING ENVIRONMENT
• PROGRAMMING LANGUAGE
dumb
• ASSEMBLY
• PROCESOR
PROGRAM ROUTINE STACKING
•
•
•
•
•
•
Graphical User Interface
Program
Operating Environment (Windows)
DISK Operating System (DOS)
Basic input/output system (BIOS)
Machine code
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)
ELEMENTARY Computer Layout
MEM
data+instructions
I/O
CPU
External
Model CPU
PC
M
A
R
M
D
R
R1
A
R2
B
ALU
IR
SR
DECODER
C
ICU
CLOCK
TIMER
Legend to the Microprocessor
•
•
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•
•
•
•
•
•
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
Z80 Processor Register Layout
Main registers.
Interupt
register
Alternative
registers.
I
R
Memory
Refresh
Accumulator
Registers
A’
W
B
D
H
I
I
S
P
Z
C
E
L
X
Y
P
C
W’
B’
D’
H’
Z’
C’
E’
L’
A
Alternative Registers
Adress Registers
F
F’
Flags 8 bit
S
Z
H
Sign
Zero
Half-Carry
P/V Parity/overfl.
N
Negate
C
Carry