1.4 s4: Packet transmission halts on occurrence of excessive collisions
Description
The LAN8650/1 may lock up and stop transmitting Ethernet frames to the network if the MAC needs to drop a frame due to excessive collisions. This will only occur if the SPI host is sending transmit frames with data blocks containing both the end of one frame followed by the beginning of the next frame.
End User Implications
The LAN8650/1 may stop transmitting Ethernet frames to the network following an excessive collision event.
Work Around
In a properly configured PLCA segment, excessive collisions will never occur; should they occur, ensure that the settings of all devices on the PLCA multidrop segment are valid. For segments configured to operate in pure CSMA/CD without the benefit of PLCA, the probability of excessive collisions exists but is small. In this case the customer should evaluate the potential for frame drop due to excessive collisions and configure the SPI host to only contain one frame per transmit data block payload if necessary.