Answers Database
A1.5 Timing Analyzer: OFFSET contraints on TIMEGRPs cannot be disabled using the Disable Timing Constraints Dialog.
Record #4479
Product Family: Software
Product Line: FPGA Implementation
Product Part: Timing Analyzer
Problem Title:
A1.5 Timing Analyzer: OFFSET contraints on TIMEGRPs cannot be disabled using the Disable
Timing Constraints Dialog.
Problem Description:
Urgency: Standard
General Description: In A1.5 a new form of OFFSET constraint is permitted with the
following syntax:
TIMEGRP "group" OFFSET={IN | OUT} offset_time [units] {BEFORE | AFTER} NET
["clk_net"] [TIMEGRP "reggroup"];
For example:
TIMEGRP INPUT_PADS OFFSET = IN 20 BEFORE CLK;
Using the Timing Analyzer GUI, the Disable Constraints Dialog box (Path Filters ->
Timing Constraint Filters -> Disable Timing Constraints) cannot be used to select
and disable timing constraints of the above type.
Solution 1:
This is fixed in M1.5i and Service Packs.
A current workaround for this problem requires hand editing the PCF file.
Open the DESIGN.PCF file in a text editor and comment out the constraint that you
wish to disable.
For example:
TIMEGRP INPUT_PADS OFFSET = IN 20 BEFORE CLK;
Would become:
#TIMEGRP INPUT_PADS OFFSET = IN 20 BEFORE CLK;
Save the PCF file and then re-run the Timing Analyzer. The commented out
constraints will no longer be analyzed.
End of Record #4479 - Last Modified: 05/19/99 13:39 |
