1/2.5 Gbps Frame Reception
The timing of a normal inbound frame transfer is shown in the following figure.
Figure 1. GMII Frame Reception at 1 Gbps
100 Mbps Frame Reception
At 100 Mbps the operation of the core is unchanged. When operating at a speed of 100 Mbps, every byte of the MAC frame (from the preamble to the frame check sequence field, inclusive) is repeated for 10 clock periods to achieve the desired bit rate. See the following figure.
Figure 2. GMII Data Reception at 100 Mb/s
10 Mbps Frame Reception
The operation of the core remains unchanged. When operating at a speed of 10 Mbps, every byte of the MAC frame (from the preamble to the frame check sequence field, inclusive) is repeated for 100 clock periods to achieve the desired bit rate.