Hard Processor System Technical Reference Manual: Agilex™ 5 SoCs

ID 814346
Date 11/27/2024
Public
Document Table of Contents

15.3.2.3.2. Timestamp Correlation using ATB SYNCREQ

To correlate timestamp between fabric trace, you can use the ATB's SYNCREQ signal. The ATB bus includes the SYNCREQ synchronization request signal which forces each active trace source connected to the ATB to generate synchronization packets. The synchronization packets include a timestamp if configured to do so. The timestamps of each trace source’s synchronization packets correlate the trace messages between the various trace sources. This provides a very high level of correlation between all trace sources since each trace source generates the synchronization packets in unison.

The HPS CoreSight* trace system allows an ATB synchronization request to be generated by the fabric using cross triggers, extending the correlation of trace messages to events or trace sources in the fabric.

To correlate fabric events or fabric trace sources to the HPS’s trace sources, FPGA soft logic can connect to one of the CTI-FPGA cross trigger inputs (FPGA_CTITRIGIN[7:0]). You can configure the FPGA_CTITRIGIN signal to broadcast the trigger input’s assertion via the CTM to the CTI-GT and cause the CTI-GT etf_syncreq signal trigger output to assert. The etf_syncreq signal assertion then propagates via the ATB to each active HPS trace source and forces them to generate synchronization packets.