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AR# 21846

10.1 Timing Analyzer, Spartan-3E - Clock and I/O Timing dialog does not recognize clocks on dedicated inputs pins


When using the Clock and I/O Timing dialog within Timing Analyzer, clocks that come from a dedicated input pin are not recognized. The Clock and I/O Timing dialog is accessed by selecting Analyze->Against User Specified Paths->by Defining Clock and I/O timing within Timing Analyzer. 


A dedicated input pin is denoted by "IP" in the pin name; for example, IP_Lxxy_#.


Timing Analyzer does not recognize clocks that come from dedicated inputs in the Clock and I/O Timing dialog; however, when analyzing normal user-defined constraints, Timing Analyzer correctly analyzes clocks which come from dedicated inputs.  


The Clock and I/O dialog is typically used to analyze the design against different clock and I/O constraints than what is defined in the UCF. If you would like to change your Clock or I/O timing constraints, you can either edit the time constrains in the PCF or edit the UCF file and re-run implementation. This will be fixed in a future design tools update.

AR# 21846
Date Created 09/04/2007
Last Updated 05/19/2014
Status Archive
Type General Article