Hi,
I am wondering if anybody can provide me some clue on this. Our board uses TM4C129ENCPDT MCU and currently we are performing ESD test on it. Very often the ESD causes the Ethernet port's transmission part to stop working. The following is the observation:
1. the MCU has not experienced a reset;
2. the firmware can still see the correct incoming packet;
2. the firmware can allocate the Ethernet TX descriptor as normal and send a Ethernet packet by starting the DMA;
3. only that the packet is not put to the wire (the packet is not received by other devices in the LAN);
4. From the Ethernet activity LED everything looks normal;
5. Unplugging and plugging back the Ethernet cable does not help (the link is established by looking at the LED indicator, but the problem remains the same);
6. reset the MCU can recover the problem (pulling down the reset line).
My question is:
1. is this possibly a problem in EMAC/PHY?
2. can it be detected so that the firmware can reset the EMAC if needed (given that the link is up and looks normal) ?
Thanks.
Tianlei