si data packet format - ComPair/ComPair-tracker-FPGA GitHub Wiki
Data packet format
This page describes the data packet format for the data emitted by each silicon layer
Current format:
| number of bytes | content | comment |
|---|---|---|
| 2 | packet size | Total size of packet, including this field |
| 1 | header size | |
| 2 | packet flags | lowest 12 bits: whether asic data timed-out |
| 8 | packet time | nanoseconds since epoch |
| 1 | number of asics | |
| 2 | asic(0) number of bytes | |
| ... | ... | |
| 2 | asic(N-1) number of bytes | |
| asic(0) number of bytes | asic(0) data | |
| ... | ... | |
| asic(N-1) number of bytes | asic(N-1) data |
Asic Data:
Currently we put some PL-generated info at the head of each asic data packet, followed by the data produced by the ASIC.
| number of bytes | content | comment |
|---|---|---|
| 4 | event id | Generated by TM |
| 4 | event counter | Event number according to asic |
| 4 | trigger info | bits 0-11: local asic triggers. 12: TM's fast-or trigger. 13: TM trigger-ack. 14: force-trigger 15: cal-pulse |
| 8 | global counter | Time when VATA received the trigger. |
| 8 | live time | Running live-time counter for the VATA |
| 48 | asic data | This is the raw data produced by the asic |