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Read operands:

This stage maintains a table of instructions received from the Issue stage. Each instruction is delayed until its operands are available, that is:

• an instruction can be executed as soon as both its operands are available
• an operand is available if the register it's in is not currently being written, and will not be written by any active instruction.
• When an instruction is activated, its operands are fetched from the register file, and the required FU is instructed to begin execution
• This deals with RAW hazards.