IF -> ID -> EX -> MEM -> WB
IF : Instruction Fetch from memory
ID : Instruction decode
EX: Execution operation or calculate address
MEM Access memory operand
WB: Write result back to register
1. R-format Instruction
IF — ID — EX — MEM
2. SW
IF — ID — EX — MEM
3. LW
IF — ID — EX — MEM — WB
