UPGRADE YOUR BROWSER

We have detected your current browser version is not the latest one. Xilinx.com uses the latest web technologies to bring you the best online experience possible. Please upgrade to a Xilinx.com supported browser:Chrome, Firefox, Internet Explorer 11, Safari. Thank you!

AR# 44152

12.x EDK, XPS_LL_TEMAC_v2_03_a - The final byte of the FCS is duplicated for some transmitted frames

Description

There have been reports oftwo designs implemented in the Virtex-4 and Virtex-5 FPGA Embedded Tri-Mode Ethernet MAC blocks erroneously appending the end of some transmitted frames with an additional byte. This byte is a duplication of the final byte of the Frame Check Sequence (FCS).

If this rare issue is encountered, erroneous operation might not be consistent across multiple devices or bitstreams, might not be consistent between power or reset cycles for a given combination of device and bitstream, and will not affect every transmitted frame.

This issue is limited to the following Ethernet MAC configurations:

  • Configurations using the MII physical interface
  • 10 or 100 Mbps operation when using the RGMII physical interface
  • 10 or 100 Mbps operation when using the Tri-speed GMII physical interface (Byte PHY clocking scheme excluded)

Solution

Xilinx has developed logic which can be integrated into the Virtex-4 or Virtex-5 FPGA Ethernet MAC wrapper to correct the erroneous behavior. It resides on the PHY-side transmit path, and checks each frame for duplication of the final FCS byte. If duplication occurs, it corrects the transmit enable signaling to exclude the duplicated byte from the frame.

If you are using an older version of XPS_LL_TEMAC core in an earlier release, please upgrade to v2.03.a of the core available in EDK 12.x.

  1. Download theXPS_LL_TEMAC v2.03.a patchfrom:
    http://www.xilinx.com/txpatches/pub/applications/misc/ar44152_xpslltemac_fcs.zip
  2. Extract the archive to the local pcore directory.
  3. Clean the project implementation and re-implement the design.
AR# 44152
Date Created 02/10/2007
Last Updated 05/22/2014
Status Active
Type Known Issues
Devices
  • Virtex-4 FX
  • Virtex-5 FXT
  • Virtex-5 LXT
  • Virtex-5 SXT
Tools
  • EDK - 12.1
  • EDK - 12.2
  • EDK - 12.3
  • More
  • EDK - 12.4
  • EDK - 13.1
  • EDK - 13.2
  • Less
IP
  • XPS LL TEMAC