lw $12, 0x10($13)
The original value in $12
is irrelevant; it is replaced with
a value from memory (memory remains unchanged).
sw t,off(b) # Word at memory address (b+off) ← $t
# b is a register. off is 16-bit two's complement.
The
store word instruction, sw
,
copies data from a register to memory.
The register is not changed.
The memory address is specified using a base/register pair.
As with the lw
instruction,
the memory address must be word aligned (a multiple of four).
Look at registers $12
and $13
and memory (at right).
Write the instruction that puts the word 0xFFFFFFFF into
memory location 0x0004000C.
0xFFFFFFFF
0x00040014
sw $ ,($)
Hint: it is OK to specify the 16-bit offset as a signed decimal integer.