AR# 71191


UltraScale+ FPGA Integrated Endpoint Block for PCI Express / PCIe UltraScale+ 4c / UltraScale Architecture PHY for PCI Express (Vivado 2018.1) - Link does not train in Gen1 design with Refclk at 125 MHz and 250 MHz speeds


Version Found: Vivado 2018.1

Version Resolved and other Known Issues:

When selecting a system Reference Clock at the 125 Mhz or 250 Mhz frequency, along with PCI Express Gen1 speed selection (2.5 GT/s), the generated core fails to link train in both hardware and simulation. 

This is because the incorrect TXOUTCLK source is selected in the GT Wizard subcore, causing the TXPROGDIV_OUT to not be driven correctly. This stalls link training at txprogdiv_reset_done.

Additionally, if you generate the GT Wizard as part of the Example Design, the design will not synthesize due to a port mismatch.



This article is part of the PCI Express Solution Centre


(Xilinx Answer 34536) Xilinx Solution Center for PCI Express


The issues listed in this answer record will be fixed in a future release of the core.

For instructions on installing the patch, please check the instructions in the 'patch_readme' directory in the attached patch file.

This patch is specifically for the UltraScale+ FPGA Integrated Endpoint Block for PCI Express, PCIe UltraScale+ 4c, and UltraScale Architecture PHY for PCI Express in Vivado 2018.1.

Note: The "Version Found" lists the version where the problem was first discovered. 

The problem also exists in earlier versions, but no specific testing has been performed to verify earlier versions.

Revision History:

06/12/2018 - Initial Release


Associated Attachments

Name File Size File Type 3 MB ZIP

Linked Answer Records

Associated Answer Records

Answer Number Answer Title Version Found Version Resolved
71147 DMA / Bridge Subsystem for PCI Express (Vivado 2018.1) - Tactical patch for issue fixes N/A N/A
AR# 71191
Date 06/15/2018
Status Active
Type Known Issues
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