Answers Database
TRCE: How to analyze overall timing constraint performance
Record #2728
Product Family: Software
Product Line: FPGA Implementation
Product Part: trce
Problem Title:
TRCE: How to analyze overall timing constraint performance
Problem Description:
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 - Last Modified: 05/28/99 09:04 |
