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AR# 51884

Design Advisory for Kintex-7 and Virtex-7 FPGA GTX Production Silicon CDR Attribute Updates


This answer record covers the CDR attribute updates optimized for GTX production silicon. The 7 Series FPGAs Transceivers Wizard v2.3 included with ISE 14.3/Vivado 2012.3 design tools has these optimized settings. For any protocols/applications that use non-scrambled 8B10B encoding such as Gigabit Ethernet, XAUI, CPRI, etc., it is recommended to update to these new values if you are using the GTX wrapper output from earlier versions of the Wizard.


This table provides the optimized CDR attribute values for non-scrambled 8B/10B encoding-based protocols in GTX production silicon when using LPM equalization mode.

RX_DEBUG_CFG 12'h000
Full-rate: Line rate <= 6.6Gbps (RXOUT_DIV=1) Half-rate: Line rate 1.6 to 6.25Gbps (RXOUT_DIV=2) Quarter-rate: Line rate 0.8 to 3.125Gbps (RXOUT_DIV=4) One-eighth rate: Line rate 0.5 to 1.5625Gbps (RXOUT_DIV=8)

CDR setting < +/- 200 ppm 72'h03_0000_23FF_1040_0020

CDR setting < +/- 700 ppm 72'h03_8000_23FF_1040_0020

CDR setting < +/- 1250 ppm 72'h03_8000_23FF_1040_0020

CDR setting < +/- 200 ppm 72'h03_0000_23FF_1020_0020

CDR setting < +/- 700 ppm 72'h03_8000_23FF_1020_0020

CDR setting < +/- 1250 ppm 72'h03_8000_23FF_1020_0020

CDR setting < +/- 200 ppm 72'h03_0000_23FF_1010_0020

CDR setting < +/- 700 ppm 72'h03_8000_23FF_1010_0020

CDR setting < +/- 1250 ppm 72'h03_8000_23FF_1010_0020

CDR setting < +/- 200 ppm 72'h03_0000_23FF_1008_0020

CDR setting < +/- 700 ppm 72'h03_8000_23FF_1008_0020

CDR setting < +/- 1250 ppm 72'h03_8000_23FF_1008_0020

Linked Answer Records

Associated Answer Records

Answer Number Answer Title Version Found Version Resolved
42946 Design Advisory Master Answer Record for Kintex-7 FPGA N/A N/A
AR# 51884
Date Created 09/18/2012
Last Updated 10/12/2012
Status Active
Type Design Advisory
  • Kintex-7
  • Virtex-7