Primary debug scenario

Symptom: Video pipeline stalls mid-frame. Upstream produces data. Downstream never sees TLAST.

Triage steps

1. Count beats since last TLAST — is upstream sending the right packet length?

2. Check TREADY backpressure — is downstream stalling?

3. If width converter in path: verify TLAST isn't swallowed during conversion.

4. Check TDEST routing if stream switch is in the path.

5. Reduce to single-packet test with known beat count.

Common pitfalls

• TLAST missing on final beat — downstream waits forever for packet end.

• Choosing AXI4-Lite for a data mover without checking single-transfer throughput and outstanding limits.

• Ignoring TKEEP on odd-sized final beats.