Instruction/Machine Cycle of stored-program computer - repeat all day

1. Fetch Instruction - read instruction pointed at by the program counter (PC) from memory into Instr. Reg. (IR)

2. Decode Instruction - figure out what kind of instruction was read

3. Fetch Operands - get operand values from the memory or registers

4. Execute Instruction - do some operation with the operands to get some result

5. Write Result - put the result into a register or in a memory location

(Note: Sometime during the above steps, the PC is updated to point to the next instruction.)