SPRUIU1C July 2020 – February 2024 DRA821U , DRA821U-Q1
Ethernet port N (where N = 1 to 4)
The total number of frames received on a port that overran the port’s receive FIFO and were dropped (bottom of receive FIFO). Port 0 (CPPI receive port) should not drop packets on receive because port 0 receive flow control should be enabled. The Ethernet ports will only drop packets in the receive FIFO when receive flow control is enabled and the sending port ignores sent pause frame and then overruns the receive FIFO. An overrun frame is defined to be:
This statistic should be zero if proper flow control is being followed.
Host port 0
This statistic also counts frames dropped on port 0 that were 17 to 63 bytes (only for port 0). For Ethernet ports, the drop count for frames shorter than 33 bytes is included in the undersized or fragment count. Port 0 simply gives an indication that a packet was dropped. No other statistics are counted for frames shorter than 33 bytes.