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?

Description

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