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AR# 40838

Timing Design Assistant - Timing Violation Debug & Workaround

Description

General Answer Recordsthat explain how to interpret timing results and work around timing violations.

Solution

Error/Warning Codes

(Xilinx Answer 29290) - 12.1 Timing Analyzer - "WARNING:Timing:3223 - Timing constraint "%s" ignored during timing analysis."

(Xilinx Answer 32505) - 11.1 Timing Analyzer - Cross-probing with Timing Analyzer into FPGA Editor is causing warnings

Component Switching Limit violation

(Xilinx Answer 32120) - 11.1 Release Notes - PAR/Timing Analyzer/trce - Why do I see Component Switching Limit warnings in my 11.1 PAR report?

(Xilinx Answer 32108) - 11.1 Release Note - Timing Analyzer/TRCE - I see Component Switching Limit errors on a constraint that has zero items analyzed

Closure suggestion

(Xilinx Answer 9410) - 12.1 Timing Closure - Suggestions for high fanout signals

(Xilinx Answer 9411) - 12.1 Timing Closure - Timing Closure suggestions for state machine optimization

(Xilinx Answer 9412) - 12.1 Timing Closure - Suggestions for long carry logic chains

(Xilinx Answer 9413) - 12.1 Timing Closure - Suggestions for I/O 3-state enable paths

(Xilinx Answer 9414) - 12.1 Timing Closure - Suggestions for paths through TBUFs or other intermediate points

(Xilinx Answer 9415) - 12.1 Timing Closure - Suggestions for timing through irrelevant paths such as RESET or ".SR" pin

(Xilinx Answer 9416) - 12.1 Timing Closure - Suggestions for using multi-cycle paths, such as a path through a ".CE" pin

(Xilinx Answer 9417)- 12.1 Timing Closure - Suggestions for how to avoid having too many levels of logic

(Xilinx Answer 9418)- 12.1 Timing Closure - Suggestions on how to avoid the timing constraint missing the goal by 5% to 10%

(Xilinx Answer 9419) - 12.1 Timing Closure - Suggestions to avoid the timing constraints missing the goal by 10% to 15%

(Xilinx Answer 14644) - 12.1 Timing Analyzer - How do I set Timing Analyzer to report asynchronous set/reset paths? (reg_sr_r & reg_sr_o)

(Xilinx Answer 12829) - 12.1 Timing Closure/Timing Analyzer - How do I ensure that my design meets timing requirements/optimize for speed?

(Xilinx Answer 3888) - 12.1 Timing Closure - How does Timing Analyzer list the number of timing errors?
(Xilinx Answer 12770) - 11.1 Timing Analyzer/Constraint - Adding support for CLKIN_DIVIDE_BY_2 property on the DCM/PLL/MMCM

Usage

(Xilinx Answer 9467) - 12.1 Timing Analyzer - Can I re-run Timing Analyzer with modified timing constraints to obtain an updated timing report?
(Xilinx Answer 2945) - 12.1 Timing Analyzer - How does Timing Analyzer calculate worst-case timing values if I do not know the temperature grade?
(Xilinx Answer 2425) - 12.1 Timing - How do I prorate an industrial temperature grade device?
(Xilinx Answer 25186) - 13.1 Timing - Master Answer Record on Analysis of Different Temperature Grades (Military, Industrial, Commercial)
(Xilinx Answer 33742) - 11 Timing Analyzer - Why doesn't Timing Analyzer parse TWR files anymore?
(Xilinx Answer 4235) - 12.1 Timing - What temperature was used to obtain the results in the Timing Analyzer data sheets (Military vs. industrial parts)?
(Xilinx Answer 32458) - 11.1 Timing Analyzer Release Note - How do you cross-probe to FPGA Editor from Timing Report?
(Xilinx Answer 32383) - 11.1 Release Note - Timing Analyzer/PlanAhead - Timing parameter link opens data sheet, but "No matches were found."
(Xilinx Answer 19555) - 12.1 Release Note - Timing - Does Timing Analyzer provide phase shift information on external clocks generated by DCM?
(Xilinx Answer 31267) - 11.4 Timing Analyzer - Does TRACE perform any Recovery or Removal Checks in addition to setup/hold checks?
(Xilinx Answer 11163) - 12.1 Timing Analyzer - The temperature prorating function allows only up to 85 degrees C for Commercial devices. Can I derate timing at the Absolute Maximum limit?
(Xilinx Answer 12797) - 12.1 Timing Analyzer - Where is the table of time groups in the software?
(Xilinx Answer 32111) - 12.1 Known Issue - Timing Analyzer/trce - Advanced Analysis neglects Component Switching Limits

Timing Report Interpretation

(Xilinx Answer 14424) - 11.1 Timing Analyzer/NGDANNO - DDR clock-to-out times in timing simulation do not match Timing Analyzer
(Xilinx Answer 25128) - 11.1 Release Note - Timing Analyzer- Why are my Timing Analyzer Results better than the Data Sheet numbers?
(Xilinx Answer 18522) - 13.1 Timing Analyzer - Does Timing Analyzer include the flight time delay?
(Xilinx Answer 21328) - 12.1 Known Issue - Timing - Why is the spread in the data sheet section of Timing Analyzer not equal to Tdick/Tckdi?
(Xilinx Answer 34158) - 11.4 Timing Analyzer - Reports too many paths
(Xilinx Answer 33113) - 11.2 Timing Analyzer - Autogenerated constraints report incorrect value for clk to pad
(Xilinx Answer 31881) - 12.1 Timing Analyzer - Why is my unconstrained path report highlighting a hold violation?
(Xilinx Answer 18576) - 12.1 Known Issue - Timing Analyzer, TRACE - Different data valid windows for a differential input can be calculated based on the information given in the data sheet section of the Timing report
(Xilinx Answer 32112) - 11.1 Release Note - Timing Analyzer/trce - Why do I have hold analysis in my TWR? I did not see this in previous versions of TRCE
(Xilinx Answer 21109) - 13.1 Timing/PAR - What is the meaning of the timing score in the Static Timing Report?
(Xilinx Answer 24446) - 13.1 Timing - Why is the number of timing errors lower than the number of actual failed paths in the timing report?
(Xilinx Answer 4313) - 12.1 Timing - What are the design statistics in the timing summary (i.e., maximum/minimum arrival input/output time)?
(Xilinx Answer 7013) - 12.1 Timing - The maximum delay path does not match the minimum period value in any timing report (two-phase)
(Xilinx Answer 17224) - 12.1 Release Note - Timing Analyzer/TRACE - How does clock skew affect setup/hold calculations? (Hold violation)
(Xilinx Answer 12216) - 13.1 Timing Analyzer - The Custom Analysis data sheet section does not include the Clock-to-Setup table

AR# 40838
Date Created 04/20/2011
Last Updated 12/15/2012
Status Active
Type General Article
Tools
  • ISE Design Suite - 11.1
  • ISE Design Suite - 11.2
  • ISE Design Suite - 11.3
  • More
  • ISE Design Suite - 11.4
  • ISE Design Suite - 11.5
  • ISE Design Suite - 12.1
  • ISE Design Suite - 12.2
  • ISE Design Suite - 12.3
  • ISE Design Suite - 12.4
  • ISE Design Suite - 13
  • ISE Design Suite - 13.1
  • Less