we designed a custom board using the P1020 and a GBit Phy (by Marvell) connected via the SGMII (SerDes) lines of the CPU.
During ESD evaluation of our hardware we encountered that the connection to the GBit Phy stops working under some circumstances.
All other interfaces like eLB, DDR, SDCard, 100MBit Eth, ... keep operating.
Analyzing the status of the SerDes using an 8B/10B Protocol Sniffer we found out that there are protocol violations/errors on the TX Path from the P1020 to the GBit Phy if the SerDes channels was disturbed by an ESD pulse.
We never ever did some shoots with the ESD Gun directly on the physical interface. We always shot into the ground/earth connection of the device, far away from the SerDes connection.
So, for my understanding it must have something to do with electrical or magentical fields whcih are generated by the ESD shot.
Is there anybody who has some similar experiences?
Thanks in advance for your time.