Description
I placed a timing constraint on a path, but the constraint has errors. What can I do to make this timing constraint pass?
Solution
Possible suggestions for high fanout signals: - Floorplan or LOC the origin and the global buffer of the high fanout signal.
- Duplicate the driver and tell the synthesis tool not to remove the duplicate logic.
- Use specific net fanout control on the specific net, if the synthesis tool allows.
For additional suggestions and recommendations, see the following Answer Records:
- For state machine optimization, see (Xilinx Answer 9411).
- For long carry logic chains, see (Xilinx Answer 9412).
- For I/Os 3-state enable paths, see (Xilinx Answer 9413).
- For paths through TBUFs, see (Xilinx Answer 9414).
- For timing through irrelevant paths such as RESET or ".SR" pin, see (Xilinx Answer 9415).
- For using multi-cycle paths, such as a path through a ".CE" pin, see (Xilinx Answer 9416).
- To avoid having too many levels of logic, see (Xilinx Answer 9417).
- For timing constraints that miss their goals by 5% to 10%, see (Xilinx Answer 9418).
- For timing constraints that miss their goals by 10% to 15%, see (Xilinx Answer 9419).