Instruction Cycle, Fetch Cycle and Execute Cycle in 8085 Microprocessor (Study Notes)

Instruction Cycle in 8085 Microprocessor

[Diagram of Instruction Cycle ]

The necessary states that the CPU carries out to fetch an instruction and necessary data from the memory and to execute it, constitute an instruction cycle.
The necessary steps which are carried out to fetch an op-code from the memory constitute a Fetch Cycle.
The necessary steps which are carried out to get data, if any, from the memory and perform specific operation specified by op-code, constitutes an Execute Cycle.

You can say,

Instruction Cycle = Fetch Cycle + Execute Cycle

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