1.3 s3: RMII CSMA/CD operation in mixed PLCA segments

Description

The LAN8670/1 RMII cannot be operated with PLCA disabled on a network with other PLCA-enabled nodes. When the device is configured for CSMA/CD operation (i.e., PLCA is disabled), then the reception of PLCA BEACON and COMMIT symbols from the network will be improperly transferred via the RMII to the MAC resulting in undefined behavior including dropped packets.

The LAN8672 does not support RMII operation.

End User Implications

The RMII may only be used with PLCA disabled when all other nodes on the mixing segment are also configured for pure CSMA/CD operation.

Work Around

None.

Resolved with the release of Silicon Rev D0.