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AR# 17316

5.2 Speed Files - What has changed in the Virtex-II Pro v1.78 speed files?


Keywords: VIIPro, Virtex-II Pro, speed, files

Urgency: Hot

General Description:
What has changed in the Virtex-II Pro v1.78 speed files?


The changes in the Virtex-II Pro speed file 1.78 are as follows:

Speed file designation
2VP7, 2VP20 dash 5 is designated as a production version.
2VP7, 2VP20 dash 6 is designated as a preliminary version.

Delay adjustments
The final measurements against silicon are completed, and adjustments are required for some resources:
Resources set slower are as follows:
Shift Reg 7%
Horizontal Long-line 3%
BRAM clock to out - 60 ps slower, for -7 only
Resources set faster are as follows:
Doubles 2%
Vertical Hex Lines 1%
All other resources within 1% and changed only to better fit predictions.

Equation adjustment
- Pin-to-Pin Parameters in the Data Sheet section of timing report
The pin-to-pin setup/hold time numbers using DCM include worst case from both rising edge and falling edge of the clock. There is no change to the equation compared to 1.76. However, the setup/hold delay increases to more correctly reflect worse case measurement data on production devices. (1.76 setup/hold data was an estimate).

- The DERATE parameter was not taken into consideration in the relative min. calculation. Consequently, the resulting Hold delay is bigger than it needs to be. This problem is fixed in the latest 5.2i Service Pack, available at:
The first service pack containing the fix is 5.2i Service Pack 3.
The first Virtex-II Pro speed file containing the fixes is version 1.78.
The first Virtex-II Pro data sheet containing the fixes is version 2.8 (May 27, 2003).
Reference the Virtex-II Pro DC and Switching Characteristics (Module 3):
AR# 17316
Date 05/17/2006
Status Archive
Type General Article
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