Question

(MIPS Assembly Language):

Assume the following piece of MIPS code:

label1:

.text 0x4000fc
lui $t0, 1022
ori $t0, $t0, 2048
srl $t1, $t0, 18
sw $t0, 101($t1)
slti $t2, $t1, 5
beq $t2, $0, label3

label2:...

...
label3:...
a) The code modifies a word in memory at the following address (circle one):

1. (i) 1022

2. (ii) 101

3. (iii) 5

4. (iv) 10220000

5. (v) Other (provide your own answer): _________________

b) The following value is stored in memory (circle one):

1. (i) 0x17

2. (ii) 0

3. (iii) 1023

4. (iv) 67043320

5. (v) Other (provide your own answer): ___________________

c) After the branch instruction is executed, the program will continue at (circle one):

(i)label1 (ii) label2 (iii) label3 (iv) The program does not continue

d) Show the sequence of addresses issued by the CPU to execute the code (the first five instructions only):

Address	R/W	Data Bus	Comments(optical)

Answer 1

lui $t0, 1022
$t0 = 0000 0000 0000 0000 0000 0011 1111 1110

ori $t0, $t0, 2048
$t0 = 0000 0000 0000 0000 0000 1011 1111 1110 (2048 + 1022 = 3070)

srl $t1, $t0, 18
$t1 = 0000 0000 0000 0000 0000 0000 0000 0000

sw $t0, 101($t1)
Mem[$t1 + 101] = $t0

a) The code modifies a word in memory at address = 101
b) value is stored in memory = 3070
c) As $t1=0 and ($t1 < 5) $t2=1
After the branch instruction is executed, the program will continue at label2

(d)the sequence of addresses issued by the CPU to execute the code
0x4000fc
0x400100
0x400104
0x400108
0x40010c