Flashcards
The Fetch-Decode-Execute Cycle
Cards in this deck (6)
- 1What are the three stages of the Fetch-Decode-Execute cycle?1. Fetch
2. Decode
3. Execute - 2Describe the Fetch phase1. Address of the next instruction copied from the PC to the MAR
2. Instruction held at that address is copied to the MDR; contents of the PC is incremented
3. Contents of the MDR copied to the CIR - 3Decode PhaseThe instruction held in the CIR is decoded - split into opcode and operand
- 4What does the opcode hold?The type of instruction to be carried out
- 5What does the operand hold?Either:
1. The address of the data to be used within the operation, or
2. The actual data to be operated on - 6Outline the events in the Execute phaseThe instruction is executed. This may involve reading from/writing to main memory, or the data may be passed on to the ALU/FPU/general purpose registers
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- A level OCR A level Computer Science (Topic 1 - Components of a Computer) Flashcards on The Fetch-Decode-Execute Cycle, created by James Norman on 09/11/2018.
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- James Norman
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