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AR# 36075

Design Assistant for PCI Express - 128-bit interface with packet straddling


This answer record is the starting point for questions regarding the 128-bit interface and packet straddling.

Note: This Answer Record is a part of the Xilinx Solution Center for PCI Express (Xilinx Answer 34536). The Xilinx Solution Center for PCI Express is available to address all questions related to PCIe. Whether you are starting a new design with PCIe or troubleshooting a problem, use the Solution Center for PCIe to guide you to the right information.


The x8 Gen 2 core uses a 128-bit TRN interface. Received packets may not always start on bits 128:121, but may start at other places in the 128-bit bus. These straddled packets can be interpreted using the trn_trem_n bus. See the core's User Guide (UG517) for more information on how to read the straddled packets in the "Receiving Inbound Packets" section. See (Xilinx Answer 35920) to help locate the correct User Guide. There is no option to have the core de-straddle packets for the user.

Revision History
08/13/2010 - Initial Release

Linked Answer Records

Associated Answer Records

AR# 36075
Date Created 08/02/2010
Last Updated 03/04/2013
Status Active
Type General Article
  • Virtex-6 CXT
  • Virtex-6 HXT
  • Virtex-6 LXT
  • Virtex-6 SXT
  • Virtex-6 FPGA Integrated Block for PCI Express ( PCIe )