Instruction Cycle
• Each phase decomposed into sequence of elementary micro-operations
• E.g. fetch, indirect, and interrupt cycles
• Execute cycle
—One sequence of micro-operations for each opcode
• Need to tie sequences together
• Assume new 2-bit register
—Instruction cycle code (ICC) designates which part of cycle processor is in
– 00: Fetch
– 01: Indirect – 10: Execute – 11: Interrupt