Definition
Multi-Cycle Processor
A multi-cycle processor is a processor in which one instruction is executed over several clock cycles.
The work of an instruction is split into shorter phases, such as fetch, decode, execute, memory access, and write-back. Different instructions may therefore require different numbers of cycles.
Trade-off
Compared with a single-cycle processor, a multi-cycle processor can use a shorter clock period and can reuse hardware across several cycles.
The cost is additional control and sequencing overhead, because the processor must coordinate several cycles for one instruction.