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AR# 16098

Virtex-II/-Pro - What is the maximum frequency of SelectMAP configuration with no handshaking (FccNH)?

Description

General Description:

What is the maximum frequency to use when configuring Virtex-II Pro using SelectMAP with no handshaking? The Virtex-II Pro documentation states that FccNH = FccSelectMAP = 50 MHz. Refer to the "Virtex-II Pro DC and Switching Characteristic (Module 3)" data sheet and see the "SelectMAP Write Timing Characteristics" table for more information at:

http://www.xilinx.com/xlnx/xweb/xil_publications_display.jsp?category=/Data+Sheets/FPGA+Device+Families/Virtex-II+Pro&iLanguageID=1

The Virtex-II documentation states that FccNH = FccSelectMAP = 66 MHz. It makes more sense for FccNH to be less than Fcc_SelectMAP.

Are the Virtex-II/-Pro numbers correct?

Solution

Virtex-II

FccNH = 50 MHz

Fcc_SelectMAP = 50 Mhz

Virtex-II Pro

The numbers for Virtex-II Pro are correct. The maximum SelectMAP CCLK frequency is (Fcc_SelectMAP), which is equal to the max SelectMAP CCLK frequency without handshaking, 50 MHz.

FccNH = FccSelectMAP = 50 MHz.

Since Fcc_SelectMAP = FccNH, handshaking is not required for the Virtex-II Pro SelectMAP configuration except for encrypted bitstreams, see (Xilinx Answer 14458).

If your design requires FccNH and FccSelectMAP to run at 66 MHz, a specific ordering code (SCD) can be attached for the following devices.

Virtex-II: XC2V1000, XC2V2000, XC2V3000, XC2V4000, and XC2V6000 devices.

Virtex-II Pro: XC2VP2, XC2VP4, XC2VP7, XC2VP20, and XC2VP30 devices.

For device availability and ordering information, contact your local FAE and sales office. Note that devices with this SCD do not support CLK2X as a feedback clock for DCMs.

AR# 16098
Date Created 09/03/2007
Last Updated 12/15/2012
Status Active
Type General Article