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

Instruction Cycle in 8085 Microprocessor

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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