Tool/software:
Hello,
We are testing 30 prototype boards using the TM4C1294. One of these boards was unable to communicate over Ethernet. When we checked the register status, we found that the following registers were different between the normal boards and the board with the issue.
(1) MR6 : EPHYANER
4bit PDF : Parallel Dtection Fault
1:A fault has been detected via the Parallel Detection function.
(2) MR16 : EPHYSTS
14bit MDIXM : MDI-X Mode
0：MDI pairs normal (Receive on TPRD pair, Transmit on TPTD pair)
(3) MR19 : EPHYMISR2
14bit ANERR：Auto-Negotiation Error Interrupt
1：Auto-negotiation error interrupt is pending.
11bit MDICO：MDI/MDIX Crossover Status Changed Interrupt
0：MDI crossover status has not changed.
The ANERR bit in EPHYMISR2 was always “1” whether the Ethernet cable
was plugged in or not.
Could you please give some possible reasons for this type of faults?
For example, if the Ethernet input/output pins are damaged by a surge or something, could this type of faults occur?
