warning:tsca_clk was determined to be a clock but was found without an associated clo

Question

Warning: Node: tsca_clk was determined to be a clock but was found without an associated clock assignment.

“tsca_clk” comes from an external device ,the clock frequency range from 8~50Mhz.how can i constrain this clock?

altera_forum · Answer

Just create a virtual clock with required frequency and waveform parameters.

altera_forum · Answer

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Just create a virtual clock with required frequency and waveform parameters.

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hi,

virtual clock? I have no idea about the required waveform.

for example,

create_clock -period 2.000 -name tsca_clk tsca_clk -waveform {0 1} ?

can the above constraints work correctly?

thx :)

altera_forum · Answer

Is this clock is driving internal logic? If yes, then it's a real clock, not virtual: create_clock -name tsca_clk -period 20.000

altera_forum · Answer

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Is this clock is driving internal logic? If yes, then it's a real clock, not virtual:

create_clock -name tsca_clk -period 20.000

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yes,it is driving internel modules,and its frequency is changeable.

the period is set as to the highest frequency?

altera_forum · Answer

Yes, so it will work with slower ones.

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