2. Read operands
2. Read operands
- When the instruction is issued, the execution unit is reserved (becomes busy)
- Operands are read in the execution unit when they are ready (i.e., are not results of still executing instructions). This prevents RAW hazards
3. Execution
- One or more cycles depending on functional unit latency
- When execution completes, the unit notifies the scoreboard it’s ready to write the result