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AR# 55857

JESD204B v4.0 or earlier - Updated RX Termination settings for 7 Series FPGA GTP and GTH

Description

When using the JESD204B v4.0 and earlier to target Artix-7 or Virtex-7 devices with GTP or GTH transceivers, the RX termination is set to GND.  

However, the latest recommendation in the GTP and GTH transceiver User Guides is to set the RX termination to 800mV. 

If using the GTX transceiver the termination is already set to 800mV.

How do I change the RX termination to 800mV for Artix-7 GTP Transceivers or Virtex-7 FPGA GTH Transceivers?

Solution

To change the RX termination to 800mV for Artix-7 FPGA GTP Transceiver:

  • in the jesd204_0_gtwizard_v2_5_0.v/vhd file, Update the following settings:
     
    RX_CM_SEL[1:0] = 2'b11
    RX_CM_TRIM = 4'b1010
    RXLPM_INCM_CFG = 1'b1
    RXLPM_IPCM_CFG = 1'b0

To change the RX termination to 800mV for Virtex-7 FPGA GTH Transceiver:

  • in the jesd204_0_gtwizard_v2_5_0.v/vhd file, change to use the following settings:
     
    RX_CM_SEL [1:0] = 2'b11
    RX_CM_TRIM = 4'b1010

Linked Answer Records

Master Answer Records

AR# 55857
Date Created 05/03/2013
Last Updated 09/11/2014
Status Active
Type General Article
Devices
  • Artix-7
  • Kintex-7
  • Virtex-7
IP
  • JESD204