Answers Database

M1 TRCE: How to analyze overall timing constraint performance


Record #2728

Product Family:  Software

Product Line:  Merged Core

Problem Title:
M1 TRCE: How to analyze overall timing constraint performance


Problem Description:
Keywords: timing, constraint, timespec, performance

Urgency: Standard

General Description:
You can enter timing constraints to tell the place and route
software the maximum period you want on some pieces of logic
and the minimum delay that you want on other pieces of logic.
How can you analyze whether the place and route software
was able to meet your constraints, and what are actual delays and period?


Solution 1:

Timing Reports:

  Graphical Tools:
    The Report Browser contains 2 timing reports:
	  - Logic Level Timing Report
	  - Post Layout Timing Report

    The Logic Level Timing Report is produced after the Map stage.  The
    times reported are based on the actual block delays and estimates
    for the route delays.

    The Post Layout Timing Report is produced after the Place and
    Route stage.  The times reported here are based on real block and
    real route delays.

    By default, both reports automatically report the performance of all
    of the timing constraints.	If reports give detailed path analysis
    instead of a  summary, check the following:

	1. In the Design Manager, select the revision that you are
	   analyzing.

	2. Click on the Flow Engine button and from the Flow Engine
	   menu, select Setup->Options.

	3. In the Options dialog, click on the Edit Template button
	   for the Implementation Template.

	4. On the Implementation Template, click on the Timing Tab.
	   Make sure that Design Performance Summary is selected.

    NOTE: The Logic Level Timing Report and Post Layout Timing Report
	  are not produced by default.	In order to produce the reports:

	1. In the Design Manager, select the revision that you are
	   analyzing.

	2. Click on the Flow Engine button and from the Flow Engine
	   menu, select Setup->Options.

	3. In the Options dialog, select Produce Logic Level Timing
	   Report to enable the Flow Engine to create the Logic Level
	   Timing Report.  Select Produce Post Layout Timing Report
	   to enable the Flow Engine to create the Post Layout Timing
	   Report.  Click on OK to save the settings.

	4. The Flow Engine will produce the Logic Level Timing
	   Report in the Map stage if the Produce Logic Level Timing
	   Report option is set.  The Flow Engine will produce the
	   Post Layout Timing Report in the Timing stage if the
	   Produce Post Layout Timing Report option is set.

  Command Line:

	A post Map timing constraint report can be generated by running
	the following command:

	   trce <design name>.ncd <design name>.pcf -o <design name>.twr

	    - where <design name>.ncd and <design name>.pcf are
		    the output of map

	    - The timing constraint report will be in <design name>.twr

	A post place and route timing constraint report can be generated
	by running the following command:

	   trce <design name>.ncd <design name>.pcf -o <design name>.twr

	    - where <design name>.ncd and <design name>.pcf are
		    the output of par

	    - The timing constraint report will be in <design name>.twr


Sample of Timing Constraint Report:

================================================================================

Timing constraint: NET "I0/CLK" PERIOD =  25 nS   HIGH 50.000 % ;
 1789 items analyzed, 0 timing errors detected.
 Minimum period is  12.597ns.
--------------------------------------------------------------------------------

================================================================================

Timing constraint: NET "I2/CLK" PERIOD =  33 nS   HIGH 50.000 % ;
 5163 items analyzed, 0 timing errors detected.
 Minimum period is  17.395ns.
--------------------------------------------------------------------------------



End of Record #2728