I-type instructions have a 16-bit imm field that codes one of the following types of information.

• an immediate operand
• a branch target offset (the signed difference between the address of the following instruction and the target label, with the two low order bits dropped)
• a memory operand displacement

For the bgez, bgtz, blez, and bltz instructions, the rt field is used as an extension of the opcode field.

Instruction		Opcode	Notes
addi	rt, rs, imm	001000
addiu	rt, rs, imm	001001
andi	rt, rs, imm	001100
beq	rs, rt, label	000100
bgez	rs, label	000001	rt = 00001
bgtz	rs, label	000111	rt = 00000
blez	rs, label	000110	rt = 00000
bltz	rs, label	000001	rt = 00000
bne	rs, rt, label	000101
lb	rt, imm(rs)	100000
lbu	rt, imm(rs)	100100
lh	rt, imm(rs)	100001
lhu	rt, imm(rs)	100101
lui	rt, imm	001111
lw	rt, imm(rs)	100011
lwc1	rt, imm(rs)	110001
ori	rt, rs, imm	001101
sb	rt, imm(rs)	101000
slti	rt, rs, imm	001010
sltiu	rt, rs, imm	001011
sh	rt, imm(rs)	101001
sw	rt, imm(rs)	101011
swc1	rt, imm(rs)	111001
xori	rt, rs, imm	001110