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AR# 32748

Virtex-5 GTX FPGA RocketIO Wizard v1.6 - Release Notes and Known Issues


This Release Notes and Known Issues Answer Record is for the Virtex-5 FPGA GTX RocketIO Wizard v1.6 and contains the following information: 


- New Features 

- Bug Fixes 

- Known Issues




For the most recent updates to the IP installation instructions for this core, please go to: 


For system requirements: 


This file contains Release Notes for the Xilinx Virtex-5 FPGA GTX Transceiver Wizard v1.6. For the latest core updates, see the product page: 





- Support for ISE Design Suite 11.2  


- Clock correction sequence length options have been updated. Please refer to (Xilinx Answer 32164) for additional information. 


- Fabric Clock Correction Module. When a 16-bit RX interface is selected with 8b10b decoding, a 1-byte clock correction sequence length is possible only through the use of the new CC_2B_1SKP module. When a clock correction sequence length of 1-byte is selected on page 8 of the GUI, the Wizard generates one CC_2B_1SKP module for each GTX Transceiver in a tile. Please refer to the "Virtex-5 FPGA RocketIO GTX Transceiver Clock Correction Module" (XTP037) for additional information regarding the module. 


- New directory structure for the generated example design. Please refer to the Getting Started Guide (UG204) for additional information: 




- For some of the designs, timing closure at fabric rates of 312.5 MHz and higher might require significant effort. For best results, use a 16/20/32/40 bit interface for line rates higher than 2.5 Gb/s. 


- When using RXRECCLK to generate RXUSRCLK/2, it is possible that the design will not meet timing. Please refer to (Xilinx Answer 32996) for more information. 


- RST not held for 3 CLKIN cycles simulation warning. Please see (Xilinx Answer 32230) for more information. 


- Might observe X's and timing simulation failures when doing back annotated simulation if using either the tx_sync deskew module or the fabric clock correction module. 


- For 1-byte Example Design, X's might propagate from the GTX to user logic.  


- Simulation warning related to the FIFO used in the external Clock Correction module. Please see (Xilinx Answer 33925) for more information. 


- It is very difficult for the external Clock Correction module to meet timing at line rates above 5Gb/s and has not been verified to operate above that rate. At rates greater than 5Gb/s, the operation of this module is not guaranteed or supported. 


The most recent information, including known issues, work-arounds, and resolutions for this version is provided in the Release Notes Answer Record for the ISE Design Suite 11.2 IP Update at: 




To obtain technical support, create a WebCase at www.xilinx.com/support. Questions are routed to a team with expertise using this product. 


Xilinx provides technical support for use of this product if used according to the guidelines described in the core documentation, and cannot guarantee timing, functionality, or support of this product for designs that do not follow specified guidelines. 




Date By Version Description 


06/24/2009 Xilinx, Inc. 1.6 ISE 11.2 Release, Fabric Clock Correction module 

09/18/2008 Xilinx, Inc. 1.5 TXT support, Lane-to-lane Deskew module 

06/27/2008 Xilinx, Inc. 1.4 OBSAI, PCIe Gen2, OOBDETECT_THRESHOLD update 

04/25/2008 Xilinx, Inc. 1.3 Optimized CDR attributes 

03/24/2008 Xilinx, Inc. 1.2 Initial release 


AR# 32748
Date Created 06/24/2009
Last Updated 11/10/2014
Status Active
Type General Article