Answers Database
M1.5: TRCE: WARNING:bastw:544 - Clock nets using non-dedicated resources were found
Record #5804
Product Family: Software
Product Line: FPGA Implementation
Product Part: trce
Product Version: 1.5is1
Problem Title:
M1.5: TRCE: WARNING:bastw:544 - Clock nets using non-dedicated resources were found
Problem Description:
Urgency: HOT
General Description: PAR will not include clock skew in a period analysis
if a clock is routed on the secondary backbone of virtex. After running
TRCE you will recieve this warning:
WARNING:bastw:544 - Clock nets using non-dedicated resources were
found in this design. Clock skew on these resources will not be
automatically addressed during path analysis. To create a timing report
that analyzes clock skew for these paths, run trce with the '-skew' option.
Solution 1:
It should be noted that this warning does not mean that no global resources
were used; only that some nets which could be classified as "clock" nets
are not on global clock resources.
Solution 2:
Follow the suggestion in the warning and run TRCE with the -skew option.
This will analyze the design including the clock skew in the PERIOD
constraint. If the addition of the clock skew causes the PERIOD
constraint to fail, the design will need to be run through PAR again.
Before this is done a environment variable needs to be set to tell PAR
to include the skew when it tries to meet timing. Set the following
environment variable: XILINX_DOSKEWCHECK=1
Solution 3:
If there is a BUFG unused, route this clock using that resource. Clocks
that are routed using BUFGs, will have their skew included by PAR.
End of Record #5804 - Last Modified: 05/28/99 13:41 |
