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AR# 51554

Design Advisory for Aurora 64B66B v8.1 or earlier - Core initialization is inconsistent on consecutive RESET and PMA_INIT inputs


Aurora 64B66B v8.1 and earlier versions of the IP core are sometimes unstable during initialization when a RESET/GT_RESET_IN input is applied to the IP multiple times.

This is observed when the core is targeted to the Xilinx 7-series devices. 

This answer record provides recommendation to have a stable Aurora 64B66B core


All of the issues found in initialization phase with Aurora 64B66B v8.1 and earlier have been fixed in Aurora 64B66B v9.0 core. 

Please refer to the change log or (Xilinx Answer 54368) for more details.

Recommendation for Aurora64B66B core targeting 7 series devices

Designs using Aurora 64B66B v8.1 and earlier that have not completed production testing are required to upgrade to Aurora 64B66B v9.0 core available in Vivado 2013.3. 

Designs using Aurora 64B66B v8.1 and earlier that are in production and have passed verification do not need to take any action.

Upgrading to Aurora 64B66B v9.0:

Please refer to the Migrating section in the LogiCORE IP Aurora 64B/66B V9.0 Product Guide for Vivado Design Suite:

Guidelines for designs using ISE targeting 7 series device:

Xilinx does not plan to make any updates to the Aurora 64B66B v7.3 released in ISE 14.3 that supports 7 series devices.

Xilinx recommends migrating the design to Vivado Design Suite and use Aurora 64B66B v9.0 for designs targeting 7 series devices.

Major changes in Aurora 64B66B v9.0

  • Aurora 64B66B v9.0 supports only Verilog source code.
  • VHDL users can use the netlist only mode through Out Of Context flow.
    Please refer to the Migrating section in the LogiCORE IP Aurora 64B/66B V9.0 Product Guide for Vivado Design Suite.
    Aurora 64B66B v9.0 has several ease of use and debug features implemented as part of the example design.
    Please refer to the change log or (Xilinx Answer 54368) for more details.

Backward compatibility with previous versions of Aurora 64B66B

Aurora 64B66B v9.0 is expected to be backward compatible with previous versions of the core with same configuration using 7 series devices.

For example: 

Aurora 64B66B v9.0 with configuration of type x is not expected to have any issues interfacing with an already in production design that has Aurora 64B66B v8.1 with the same configuration in 7 series device.

After the 2013.3 release, Xilinx plans to validate Aurora 64B66B v9.0 with Aurora 64B66B v8.1 in 7 series devices and publish the results in this answer record.

Additionally, Xilinx plans to do interoperability test between Aurora 64B66B v9.0 targeting 7 series with Aurora 64B66B v7.3 targeting 6 series devices.

Fixes done in Aurora 64B66B v9.0

Xilinx strongly recommends upgrading to the Aurora 64B66B v9.0 core. 

The list below includes some of the significant IP changes in v9.0.

Fixes done in the Reset and Initialization part of the Aurora 64B66B v9.0 core

Symptoms Cause Fix Details
Tx data corruption
Due to warm reset Using stable clock to synchronize the MMCM Lock signal
Rx data corruption After any reset Reset Rx buffer after CDR lock is established
Hot-Plug causing soft errors Asynchronous resets on link partners Providing early indication of reset to remote agent in hot plug sequence

Fixes done in Architecture part of the Aurora 64B66B v9.0 core

Category Cause Fix Details
Architecture Change Architecture Robustness  32 bit Rx path for increased skew margin. Addition of CB error handling and removal of redundant logic(PPM compensation logic and per lane pointer comparisons)
Robustness Fix Distributed RESET logic Common Reset sequencing across all lanes, removes per lane reset synchronizers across recovered clock and user clock
Feature enablement Polarity inversion RTL is updated to enable polarity inversion functionality

Please contact an FAE or I/O specialist for more details about the fixes.

Revision History
10/23/2013 - Initial release

Linked Answer Records

Master Answer Records

Answer Number Answer Title Version Found Version Resolved
42944 Design Advisory Master Answer Record for Virtex-7 FPGA N/A N/A
42946 Design Advisory Master Answer Record for Kintex-7 FPGA N/A N/A
AR# 51554
Date 01/08/2015
Status Active
Type Design Advisory
  • Kintex-7
  • Virtex-7
  • Aurora 64B/66B