UPGRADE YOUR BROWSER

We have detected your current browser version is not the latest one. Xilinx.com uses the latest web technologies to bring you the best online experience possible. Please upgrade to a Xilinx.com supported browser:Chrome, Firefox, Internet Explorer 11, Safari. Thank you!

AR# 40124

Virtex-5 GTP GTX - Use of TERMINATION_CTRL and TERMINATION_OVRD

Description

Due to a error in my PCB design, both calibrating resistor RREF and MGTAVTTRXC are missing. Is there a way to set the RX termination resistor value?

Solution

The receiver terminating resistor calibration is performed automatically one time during the configuration process. All analog supply voltages must be present and within the proper tolerance as specified in the Virtex-5 FPGA Data Sheet. MGTAVTTRXC powers the RX terminating resistors calibration circuit. RREF is the precision resistor that must be positioned close to the FPGA and minimizing parasitics.

If due to a design mistake, the power or the resistor or both are not present, the terminating resistor value can be overwritten independently for each transceiver by using the TERMINATION_CTRL and TERMINATION_OVRD attributes. This feature is intended for experimental purposes only and is not supported. In this way, the expected termination precision is +/- 25%.

AR# 40124
Date Created 01/18/2011
Last Updated 02/13/2013
Status Active
Type General Article
Devices
  • Virtex-5 FXT
  • Virtex-5 LXT
  • Virtex-5 SXT
  • Virtex-5 TXT