Troubleshooting

This section describes some of the common issues that can arise when using the mezzanine card.

Auto-negotiation not working #

Many issues can lead to a failure to auto-negotiate a link. Here are some of the most common issues that can occur:

Mirror Mode not enabled (Rev-A only) #

Problem: #

The Ethernet FMC Max requires Mirror Mode to be enabled in the TI PHY ( DP83867 , Port Mirror Enable bit 0 in CFG4 register address 0x0031). In the Rev-A boards (serial numbers 800000-800019), this option is not enabled by the strap resistors and must be enabled by software.

Solution: #

If you have a Rev-B or more recent revision board, Mirror Mode is enabled by strap resistors, so you should not have to enable it by software.

If you have a Rev-A board, our reference designs already include the software required to enable Mirror Mode. If you have built your own custom design, you will need to add software to enable Mirror Mode in the PHY. This can be done by writing a 1 to bit 0 of PHY register CFG4 at address 0x0031 (note that this register is in the extended address space). If you are using Linux, you can enable Mirror Mode in the device tree by including the boolean property enet-phy-lane-swap (see our AXI 1G Ethernet reference design for an example).