CSC103 Assembly Language Exercises and Solutions

LOD-C 1

Exercise 1

initialize the contents of several variables to 0

; Exercise 1
; D. Thiebaut
; Initialize the contents of several variables 
; to 55

start:
		lod-c	55		; put 0 in acc
		sto		var1	; store acc in var1
		sto		var2	; store acc in var2
		sto		var3	; store acc in var3
		hlt

@10					; the data section starts here
var1:	        data
var2:	        data
var3:	        data

LOD 10/STO 10

Exercise 2

increment a counter

; Exercise 2
; D. Thiebaut
; A program that sets a counter to 0
; and then increments it
;
start:	lod-c	0		        ; first initialize the counter to 0
		sto	counter

; increment counter
		lod	counter	; get counter in acc
		add-c	1		; add 1 to acc
		sto	counter	; store acc in counter

		hlt

@10						
counter:	data

Exercise 3

compute sum of 3 variables

; Exercise 3
; D. Thiebaut
; Compute the sum of 3 variables
; and stores it into a 4th variable called
; sum.

start:	lod		var1	; get var1 in acc
		add		var2	; add var2 to acc
		add		var3	; add var3 to acc
		sto		sum		; store acc into sum
		hlt

@10
var1:	12
var2:	5
var3:	3
sum:	0

LOD-I 10/STO-I 10

'Exercise 4:

create an index and use it to sum up the same 3 variables

JMP instruction and labels

Exercise 5

create an infinite loop (incrementing a variable, for example)

Exercise 6

create an infinite loop that clears the memory starting at 10

Exercise 7

why does the program of Exercise 6 stop?

JMZ

Exercise 8

write a loop that loops 10 times (use a counter)

Exercise 9

write a loop that stores 55 in the memory locations between 15 and 30