AR# 5352

Description

General Description: NGDBUILD issues the following error

ERROR:bascp:47 - Invalid UCF/NCF file entry value detected while reading UCF.

This error message can be the result of a UCF file written by the Constraint

Editor. If the ngd file, read into Constraint Editor, contains the following:

NET "CLK" TNM = "CLK";

TIMESPEC TS_CLK = PERIOD : "CLK": 25 : HIGH : 50%;

The Constraint Editor will translate this constraint incorrectly. In the Source

Constraints Tab (read-only) the following constraint will be displayed:

INST "CLK.PAD" TNM = "CLK";

TIMESPEC "TS_CLK" = PERIOD "CLK" 25000.000 ps LOW;

50% missing and the HIGH keyword has changed to LOW.

This results in the following constraint being written to the ucf file:

TIMESPEC "TS_CLK" = PERIOD "CLK" 25000.000000 ps LOW;

This constraint with error in ngdbuild.

Solution

To resolve this issue open the UCF file in a text editor and make the following

changes:

Change the LOW to HIGH.

Add the 50%.

Here is the corrected constraint:

TIMESPEC TS_CLK = PERIOD : "CLK": 25 : HIGH : 50%;