Description

Solution

To define the appropriate I/O standards, you must add them in the User Constraint File (UCF).The next example shows the correct UCF format:

NET "RDat_P(0)" IOSTANDARD = LVDS_25_DCI;

This example defines the RDat_P(0) bit to have an I/O with LVDS 2.5 volts with internal device termination.

Other supported standards are listed below. Each group of signals has different supported standards for each specific device family. Note that Virtex-6 FPGA does not support LVTTL. For Virtex-7 and Kintex-7, "LVDS" is only supported in the 1.8V High-Performance I/O banks and "LVTTL" and "LVDS_25"are only supported in the High-Range I/O Banks.

SysClk

Virtex-4: LVPECL_25, LVDS_25, LVDS_25_DCI

Virtex-5: LVPECL_25, LVDS_25, LVDS_25 (DIFF_TERM)

Virtex-6: LVPECL_25, LVDS_25, LVDS_25 (DIFF_TERM)

Virtex-7, Kintex-7: LVDS, LVDS (DIFF_TERM), LVDS_25, LVDS_25 (DIFF_TERM)

RStat, RSClk

Virtex-4: LVTTL, LVDS_25, LVDS_25_DCI

Virtex-5: LVTTL, LVDS_25, LVDS_25 (DIFF_TERM)

Virtex-6: LVDS_25, LVDS_25 (DIFF_TERM)

Virtex-7, Kintex-7: LVTTL, LVDS, LVDS (DIFF_TERM), LVDS_25, LVDS_25 (DIFF_TERM)

TStat, TSClk

Virtex-4: LVTTL, LVDS_25, LVDS_25_DCI

Virtex-5: LVTTL, LVDS_25, LVDS_25 (DIFF_TERM)

Virtex-6: LVDS_25, LVDS_25 (DIFF_TERM)

Virtex-7, Kintex-7: LVTTL, LVDS, LVDS (DIFF_TERM), LVDS_25, LVDS_25 (DIFF_TERM)

TDat, TDClk, TCtl

Virtex-4: LVDS_25, LVDS_25_DCI

Virtex-5: LVDS_25, LVDS_25 (DIFF_TERM)

Virtex-6: LVDS_25, LVDS_25 (DIFF_TERM)

Virtex-7, Kintex-7: LVDS, LVDS (DIFF_TERM), LVDS_25, LVDS_25 (DIFF_TERM)

RDat, RDClk, RCtl

Virtex-4: LVDS_25, LVDS_25_DCI

Virtex-5: LVDS_25, LVDS_25 (DIFF_TERM)

Virtex-6: LVDS_25, LVDS_25 (DIFF_TERM)

Virtex-7, Kintex-7: LVDS, LVDS (DIFF_TERM), LVDS_25, LVDS_25 (DIFF_TERM)

Revision History
04/13/2009 - Initial Release
06/24/2009 - Updated with Virtex-6 information
05/03/2010 - Updated with Spartan-6, removed Virtex-II/-II Pro
03/01/2011 - Added Virtex-7and Kintex-7, removed Spartan-6
03/16/2011 - Updated Virtex-7 and Kintex-7 I/O Standards description
08/26/2011 - Added LVDS_25 standards for Virtex-7 and Kintex-7