If you only need to support 1,000 M mode, you can design the layout following the
requirements below. Figure 1. GMAC 1,000 M Only
Layout requirements.
The RX/TX trace length cannot exceed 6,000 mil.
Match the RXD[3:0] signal group and the RX_CTL and RX_CLK signals with trace
length to within 100 mil. Match the TXD[3:0] signal group and the TX_CTL and
TX_CLK group trace length to within 100 mil.
The routing of data and clock lanes should keep a complete reference plane.
