描述

General Description: If a .ngd or .ucf file contain a period constraint written

using the following syntax they are not picked up by the Constraint Editor.

NET CLK PERIOD = 30 ns;

解决方案

Use the following syntax to resolve this issue:

NET "CLK" TNM_NET = "CLK"

TIMESPEC "CLK" = PERIOD "CLK" 30 ns;

This syntax will be picked up by the Constraint Editor.