Name	Format	6bits	5bits	5bits	5bits	5bits	6bits	Comments (decimal nums)	Meaning (decimal nums)
bit positions		31-26	25-21	20-16	15-11	10-6	5-0
add	R	0	2	3	1	0	20	add $1,$2,$3	$1=$2+$3 (V detected)
sub	R	0	2	3	1	0	22	sub $1,$2,$3	$1=$2-$3 (V detected)
addi	I	8	2	1	64			addi $1,$2,100	$1=$2+sign_ext(100) (V detected)
addu	R	0	2	3	1	0	21	addu $1,$2,$3	$1=$2+$3
subu	R	0	2	3	1	0	23	subu $1,$2,$3	$1=$2-$3
addiu	I	9	2	1	64			addiu $1,$2,100	$1=$2+sign_ext(100)
and	R	0	2	3	1	0	24	and $1,$2,$3	$1=$2^$3
or	R	0	2	3	1	0	25	or $1,$2,$3	$1=$2v$3
andi	I	C	2	1	64			andi $1,$2,100	$1=$2^100
ori	I	D	2	1	64			ori $1,$2,100	$1=$2 v 100
sll	R	0	0	2	1	A	0	sll $1,$2,10	$1 = $2 << 10
srl	R	0	0	2	1	A	2	srl $1,$2,10	$1 = $2 >> 10
lw	I	23	2	1	64			lw $1,100($2)	$1=Memory[$2+sign_ext(100)]
sw	I	2B	2	1	64			sw $1,100($2)	Memory[$2+sign_ext(100)]=$1
lbu	I	24	2	1	64			lbu $1,100($2)	$1=0x000000 \|\| Memory[$2+sign_ext(100)]
sb	I	28	2	1	64			sb $1,100($2)	Memory[$2+sign_ext(100)] = $1[7-0]
lui	I	F	0	1	64			lui $1,100	$1=100 x 2 ¹⁶
beq	I	4	1	2	19			beq $1,$2,place (place is 104 addresses ahead)	if($1==$2) pc=pc+4+sign_ext(25<<2)
bne	I	5	1	2	fffa			bne $1,$2,place (place is 20 addresses back )	if ($1!=$2) pc=pc+4+sign_ext(-6<<2)
slt	R	0	2	3	1	0	2A	slt $1,$2,$3	if ($2 < $3) $1=1 else $1=0
slti	I	A	2	1	64			slti $1,$2,100	if ($2 < sign_ext(100)) $1=1 else $1=0
sltu	R	0	2	3	1	0	2B	sltu $1,$2,$3	if ($2<$3) $1=1 else $1=0
sltiu	I	B	2	1	64			sltiu $1,$2,100	if ($2<100) $1=1 else $1=0
j	J	2	c0f					j 12348	pc = pc+4[31-28] \|\| (12348 << 2)
jr	R	0	12	0	0	0	8	jr $18	pc = $18
jal	J	3	c0f					jal 12348	$31 = pc+4 pc = pc+4[31-28] \|\| (12348 << 2)
syscall	n/a	0	0				0xD	syscall	xfer control to OS; $v0 contains syscall code

Last updated on 11/1/04