CSC103 Homework 4 Fall 2012
--D. Thiebaut 13:26, 11 October 2012 (EDT)
Problem #1
Th program below computes the sum of all the numbers between 0 and 10. It is the final version of the program we developed in class on Thursday 10/11/12.
Note that in assembly we can place comments in the code by preceding them with semicolons. The words following a semicolons are ignored by the translator when it takes the assembly-language program and puts the mnemonics in memory.
; Sum100 program
; D. Thiebaut
; Computes the sum of all the numbers between 0 and 10
; and stores the result in variable sum.
;
@0
jmp start
;
; data section with 2 variables
;
counter: 10
sum: 0
;
; code section
;
start:
; sum <- counter
lod counter
sto sum
; counter <- counter - 1
loop:
lod counter
dec
sto counter
; if counter is 0, then jump out of loop
jmz done
; sum <- sum + counter
lod sum
add counter
sto sum
; go back to compute new sum
jmp loop
; if we reach this point, then we are done with
; the loop and sum should contain the result
done: hlt
Just to verify that the program works, copy/paste its code into the simulator (click here to get the applets). Run the program by selecting the fastest speed , and then clicking on Run.
- Question 1