Follow a program through the controller

Watch instructions prepare time points, queues feed control outputs, and measurement results return to the CPU. Select feedback-one to follow a measurement-dependent branch. Quickstart runs the same program locally.

Explore an execution

Use Play to follow execution and Next time to apply all records at the next timestamp. Select an output interval to inspect its start. Next record, under Trace records, advances one record, including within the same timestamp.

Machine state shows the controller and the selected module’s details. Instructions lists retired instructions; Measurements shows sampling, readiness and delivery. In multicore traces, Core selects the controller; the output timeline includes all cores.

Highlighted modules changed at the selected time. CPU slots show end-of-edge occupancy recorded by CpuPipelineUpdated; the register display keeps nonzero values and destinations written to zero. Queue entries follow enqueue and trigger records; output durations come from the configured mappings.

The CPU edge index is derived from its configured clock. The TCU cycle is the latest recorded cycle at or before the selected timestamp. Playback speed does not change simulation time.

Follow measurement feedback

Select feedback-one, then Measure. Qubit 0 is sampled at 480 ns. The result becomes ready at 500 ns, reaches the CPU at 505 ns, and updates execution flags at 540 ns. These stages appear separately in Measurement delivery.

Continue to 720 ns: the CPU-selected X operation starts on qubit 1. Select feedback-zero to see the same branch choose Z. In bell, two port outputs at 400 ns produce one joint CX gate.

These recordings use mock measurement outcomes. Use the Aer backend for quantum-state evolution.

Replay a local trace

From the repository root:

python3 tools/replay_trace.py PATH/TO/TRACE.jsonl

For TRACE.jsonl, the player first looks for TRACE.summary.json, then TRACE.json in the same directory. It loads clock settings and core configurations from that file. Use --summary PATH/TO/SUMMARY.json for a different filename. Without a summary, recorded events remain available; derived clock values are unavailable. Press Ctrl+C to stop the server.