Type: Answers

Area: Intellectual Property

IP Product: Triple Speed Ethernet MAC

Why does occasional truncation of received Ethernet frames occur with the TSE MAC version 7.2 under high load conditions?


The TSE MAC core (version 7.2) contains a bug which can result in the truncation of packet data if the following two conditions are met:

1) The word-alignment feature is enabled for received Ethernet frames (via the RX_SHIFT16 bit in the Rx_Cmd_Stat register)
2) The TSE MAC is receiving a “heavy load” of similarly-sized Ethernet frames (+1 or -1 byte variation in length)

To fix this problem, you can download the patch for TSE MAC version 7.2 from this link:

MegaCore® IP Library software version 7.2 SP2  -  Patch 2.02

Or you can contact Altera® support at mySupport and request the following patch for the TSE MAC core (be sure to request the patch for 7.2 SP2 "IP"  ):  MegaCore IP Library software version 7.2 SP2  -  Patch 2.02