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KURK123's avatar
KURK123
Icon for New Contributor rankNew Contributor
8 years ago

Modelsim error

I have a code which compiles correctly but when I simulate it using ModelSim, it gives me this warning: Warning: There is an 'U'|'X'|'W'|'Z'|'-' in an arithmetic operand, the result will be 'X'(es)....
Tricky's avatar
Tricky
Icon for Occasional Contributor rankOccasional Contributor
8 years ago

Outputs that are U have to come from somewhere. You need to use the simulator to follow the signals back from the output to discover what signals are uninitialised. Then you either give them an initial value or decide it is not important ( maybe there is a valid signal that marks the data as invalid anyway).

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Modelsim​ can be set to ignore warnings like this from IEEE packages. It is a simulation setting.