2.7CPU Architecture

Out-of-Order Execution Visualizer

Step through Tomasulo's algorithm with reservation stations and a reorder buffer. Watch instructions issue, execute out of order, and commit in order.

Scenarios:
Cycle 0
Speed1x

Instruction Pipeline

#InstructionIssueExec StartExec EndWBCommitStage

Execution Timeline

Instruction
1
2
3
Issue
Execute
Write-Back
Commit

Reservation Stations

Reorder Buffer

Empty — no instructions issued yet.

Issue: Instructions enter reservation stations in order.

Execute: Instructions begin when operands are ready — out of program order.

Write-Back: Results broadcast to waiting stations via CDB.

Commit: Instructions retire from ROB in program order for precise exceptions.