The signal gmii_rx_er
when asserted within the assertion window signals that a
frame was received with a detected error as shown in the following figure. In addition,
a late error can also be detected during the Carrier Extension interval. This is
indicated by gmii_rxd[7:0]
containing the hexadecimal value 0x1F, also
shown in the following figure.
Figure 1. GMII Frame Reception with Errors