AR# 9415: 12.1 Timing Closure - Suggestions for timing through irrelevant paths such as RESET or ".SR" pin
AR# 9415
12.1 Timing Closure - Suggestions for timing through irrelevant paths such as RESET or ".SR" pin
描述
I placed a timing constraint on a path, but the constraint has errors. How can I make this timing constraint pass?
解决方案
These paths can be Timing Ignored (TIG), either by paths or by net. The following syntax is for NET and PATH TIG: (Comments = #) #Net TIG; NET reset_net TIG; #Path TIG; TIMESPEC TS_TIG = FROM source_group TO destination_group TIG; For additional suggestions and recommendations, see the following Answer Records: - Suggestions for avoiding high fanout signals, see (Xilinx Answer 9410). - Suggestions for state machine optimization, see (Xilinx Answer 9411). - Suggestions for long carry logic chains, see (Xilinx Answer 9412). - Suggestions for I/Os 3-state enable paths, see (Xilinx Answer 9413). - Suggestion for paths through TBUFs, see (Xilinx Answer 9414). - Suggestions for using multi-cycle paths, such as a path through a ".CE" pin, see (Xilinx Answer 9416). - Suggestions for how to avoid having too many levels of logic, see (Xilinx Answer 9417). - Suggestions for timing constraints that miss their goals by 5% to 10%, see (Xilinx Answer 9418). - Suggestions for timing constraints that miss their goals by 10% to 15%, see (Xilinx Answer 9419).