Microprocessor Simulator 0 Help

Download 1.18 Mb.

Page	36/82
Date	18.03.2021
Size	1.18 Mb.
	#56105

1 ... 32 33 34 35 36 37 38 39 ... 82

sms32v50 (3)
sms32v50 (3), sms32v50 (6)

Bad Comment - just repeats the code
Example - 02tlight.asm - Traffic Lights

Your Task

Write all your future programs ...

with good layout
with meaningful label names
with useful comments that EXPLAIN the code
avoiding comments that state the totally obvoius and just repeat the code

Bad Comment - just repeats the code

INC BL ; Add one to BL

Useful Comment - explains why the step is needed

INC BL ; Make BL point to the next video RAM location

Example - 02tlight.asm - Traffic Lights

Contents

Example - 02tlight.asm

; ===== CONTROL THE TRAFFIC LIGHTS =============================

CLO ; Close unwanted windows.

Start:

; Turn off all the traffic lights.

MOV AL,0 ; Copy 00000000 into the AL register.

OUT 01 ; Send AL to Port One (The traffic lights).

; Turn on all the traffic lights.

MOV AL,FC ; Copy 11111100 into the AL register.

OUT 01 ; Send AL to Port One (The traffic lights).

JMP Start ; Jump back to the start.

END ; Program ends.

; ===== Program Ends ==========================================
YOUR TASK

=========

Use the help page on Hexadecimal and ASCII codes.

Work out what hexadecimal numbers will activate the

correct traffic lights. Modify the program to step

the lights through a realistic sequence.

To run the program press the Step button repeatedly or press the Run button.

To stop the program, press Stop. When the program is running, click the RAM-Source or RAM-Hex or RAM-ASCII tabs. These give alternative views of the contents of random access memory (RAM).

Also click the List File tab to see the machine code generated by the simulator and the addresses where the codes are stored.

Ports

The traffic lights are connected to port one. Imagine this as a socket on the back of the processor box. Data sent to port one goes to the traffic lights and controls them.

There are six lamps to control. Red, Amber and Green for a pair of lights. This can be achieved with a single byte of data where two bits are unused.

By setting the correct bits to One, the correct lamps come on.

Fill in the rest of this table to work out the Hexadecimal values
you need. Of course you need to know the sequence of lights
in your country.

Download 1.18 Mb.

Share with your friends:

1 ... 32 33 34 35 36 37 38 39 ... 82