Question

8. a) (3) Assume that initially registers $8 and $10 contain 4 and 8 respectively. If every byte in the data memory initially contains the value 6, show the contents (in decimal) of all registers and/or data memory locations modified by following pair of instructions:

            lui        $10,0x1004

            sw        $8,-256($10)

b) (3) Assume that initially registers $8 and $10 contain 4 and 8 respectively. If every byte in the data memory initially contains the value 6, show the contents (in decimal) of all registers and/or data memory locations modified by following pair of instructions:

            lui        $10,0x1004

            lw        $8,-256($10)

d) (3) Assume that initially registers $8 and $10 contain 4 and 8 respectively. If every byte in the data memory initially contains the value 6, show the contents (in decimal) of all registers and/or data memory locations modified by following pair of instructions:

lui        $10,0x1004

            ori       $10,$8,0x8000

Answer 1

8)

a)

Assumed :-

$8 = 4

$10 = 8

every memory byte is 6

lui $10 , 0x1004 => $10 = 0x1004

sw $8,-256($10) => memWrite32[(0x1004) - 0x100] = memWrite[0xF04] = 4

So,

$10 = 0x1004 = 4100

memory [0xF04] = 4

b)

Assumed :-

$8 = 4

$10 = 8

every memory byte is 6

lui $10 , 0x1004 => $10 = 0x1004

lw $8,-256($10) => memRead32[(0x1004) - 0x100] = memRead32[0xF04] = 0x6060606

So,

$10 = 0x1004 = 4100

$8 = 0x6060606 = 101058054

d)

Assumed :-

$8 = 4

$10 = 8

every memory byte is 6

lui $10 , 0x1004 => $10 = 0x1004

ori $10,$8,0x8000 => $10 = $8 | 0x8000 = 0x4 | 0x8000 = 0x8004

So,

$10 = 0x1004 = 4100 (first instruction)

$10 = 0x8004 = 32772(finally)