Why do I see the warning message "Ignored filter at file.sdc(line): CLK could not be matched with a clock"?

Description

In the Quartus® Prime Standard Edition Software version 23.1 and earlier, you might see some constraints targeting a user-created clock ignored by the Timing Analyzer.

Resolution

To avoid this problem, make sure the clock declaration constraint does not include any additional spaces in the -name argument. When there are additional spaces, they are included as part of the clock name. For example: 

The constraint create_clock -name {clk  }  -period 10 [get_ports clk100] should be modified to create_clock -name {clk}  -period 10 [get_ports clk100].