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AR# 20867

7.1i NGDBuild - Timing constraint from UCF file is lost in PCF depending on input HDL

Description

Keywords: UCF, Net, Period, Constraint, PCF

Urgency: Standard

General Description:
The following constraints are not properly utilized and evaluated in the design:

Old way:
Net sys_clk_pin PERIOD = 5000 ps;

Solution

Use TNM based timing constraint for PERIOD, instead of NET timing constraint.

NET sys_clk_pin TNM_NET = "sys_clk";
TIMESPEC TS_sys_clk = PERIOD "sys_clk" 5000 ps;

The fix for the NET timing constraint passage will be available in 7.1is2.
AR# 20867
Date Created 02/24/2005
Last Updated 04/17/2007
Status Archive
Type General Article