Question

computer systems!! pls answer soon

2) Determine the content of memory location named RESULT after execution of each of the following codes: Program B TEXT TEXT LDR R1,-NUM LDR RO, A LDR R2.-N LDR RI.R LDR R2.[R2) MUL RO. RI, RO MOV RO, RO LDR R1. C LOOP: LDR R3, [RII. "4 LDR R2, D MULA RO. R1, R2, RO ADDPL Ra, R0, #1 RO, RESULT STR SUBS R2, R2, #1 S: B S BNE LOOP DATA STR R0,-RESULT A: .WORD 100 S: B S B: .WORD 50 C: WORD 20 DATA D WORD 1 WORD 6 N: NUM: WORD 2,3,0,-6,1,7 RESULT:.SKIP 4 .END RESULT: .SKIP 4 END Program A) RESULT- Program B) RESULT

Answer 1

For program A:

LDR R1, =NUM

=> R1 = address of NUM

LDR R2, =N

=> R2 = address of N

LDR R2, [R2]

=> R2 = 6

MOV R0, #0

=> R0 = 0

LOOP: LDR R3 [R1], #4

=> R3 = [R1+4] = 0

CMP R3 #0

=> EQUAL

ADDPL R0, R0, #1

=> R0 = 32*R0 + 1 = 1

SUBS R2, R2, #1

=> R2 = 5

BNE LOOP

=> FALSE

STR R0, =RESULT

RESULT = 1

For program B:

LDR R0, A

=> R0 = 100

LDR R1, B

=> R1 = 50

MUL R0, R1, R0

=> R0 = 50*100 = 5000

LDR R1, C

=>R1 = 20

LDR R2, D

=> R2 = 10

MULA R0, R1, R2, R0

=> R0 = 20*10 + 5000 = 5200

STR R0, RESULT

=> RESULT = 52000