The traces you attached show a LGOOD_5(784) sent by the host for the Transaction Packet(779) sent by device after 3.110us. Hence the violation even if it exists seems to be from the host side. The latest USB 3.2 standard mentions a timeout value of 10us in Table 7-7.Our assumption is that the traces were taken between the host and Cypress Hub(1).
It seems I have not been quite clear in my post. The trace has been collected between Cypress Hub(1) and Our Testing Unit. I have now edited my original post to show this explicitly. The fact that the LecCroy trace marks the packets as H and D is how it shows which packet is from a Downstream Port (H) and which one is from the Upstream Port (D).
Therefore, based on my testing results, I can confirm that it is Cypress Hub sending LGOOD_5, violating the 3 us timer.
On the USB 3.2 having a 10 us for this timer, I'm aware of it. However, the Hub we are using is a 3.0 and our system is a 3.1. As such, we are not assuming a larger than 3 us value for this timer.
Thanks for the clarification; it makes the trace clear now and we have identified the LGOOD_5 packet sent by the hub which exceeds 3 us.
However, if we consider USB 3.0 timer value itself, it is mentioned in the Spec under section 188.8.131.52.13 that the timer period is calculated between the last symbol of the header packet and the last symbol of LGOOD sent. Since we cannot check for the difference in the two symbols from the trace, and it is only exceeding by around 100 nanoseconds, we cannot conclude definitely that it is a violation.
Thanks for your feedback. It is great that you have identified the portion of the trace pointing to the potential violation.
On your uncertainly to conclude the violation from trace, I'm not sure if I understand your point. From the trace (the Trace View), and especially from the Link Tracker View of the trace, here is my understanding:
1) TP Packet (packet 779) is sent from our testing unit to Cypress Hub (1) at time stamp (a=5113.471 025 244). This is the time for the first symbol of the packet. From the same view, the duration of the packet is 40.100 ns. That means the time at the end of this packet is b=a+40ns
2) LGOOD_5 (packet 784) is sent to acknowledge by the Hub at time stamp (c=5113.471 028 354). This is the time for the the first symbol of the packet. From the same view, the duration of this packet is 16.040ns. That means the time at the end of this packet is d=c+16ns
3) Difference between the two packets above (taken at the end symbols of each packet -based on your reference to the Standard-) is: d-a= c+16ns-a-40ns. From the trace and the time stamps c-a=3.110us. Thus, the PENDING_HP_TIMER has been violated by 86ns (=3us-3.11us+16ns-40ns)
Please correct my above calculations and understanding if they are wrong.