Operation
- Instruction execution in a microprocessor has several basic stages:
- Fetch instruction: the task of reading the next instruction from memory into the instruction register.
- Decode instruction: the task of determining what operation the instruction in the instruction register represents.
- Fetch operands: the task of moving the instruction’s operand data into appropriate registers.
- Execute operation: the task of feeding the appropriate registers through the ALU and back into an appropriate register.
- Store results: the task of writing a register into memory.
- If each stage takes one clock cycle, then we can see that a single instruction may take several cycles to complete.
