Stage Computation: irmovl P283 Figure4场6 irmov ra. rB icode:ifun←-M1[Pc] Read instruction byte rA:rB←MPc+1] Read register byte Fetch vac←M4PC+2] Read constant value vaIP tPC+6 Compute next PC Decode vaIe<0+ vaIc Perform ALU operation Execute Memor Write RrB]←vaE Write back result back PC update PC←vaP Update Pc a Formulate instruction execution as sequence of simple steps Use same general form for all instructions Processor– 14 – Processor Stage Computation: irmovl P283 Figure 4.16 ◼ Formulate instruction execution as sequence of simple steps ◼ Use same general form for all instructions irmovl rA, rB icode:ifun  M1 [PC] rA:rB  M1 [PC+1] valC  M4 [PC+2] valP  PC+6 Fetch Read instruction byte Read register byte Read constant value Compute next PC Decode valE  0 + valC Execute Perform ALU operation Memory Write R[rB]  valE back Write back result PC update PC  valP Update PC