计算机组成与体系结构

各周期的微操作

取指周期

MAR<=PC
MBR<=memory,temp<=PC+1
IR<=MBR,PC<=temp

间址周期

MAR<=IR[operand]
MBR<=memory
IR[operand]<=MBR

执行周期

视各指令而定

;ADD R1,X
MAR<=IR[operand]
MBR<=memory
temp<=R1+MBR
R1<=temp

中断周期

MBR<=PC
MAR<=push_PC_address,PC<=ISR_entry
memory<=MBR