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AR# 23818

8.2 XST- XST does not recognize the FSM when the parameter is not constrained


XST does not recognize the FSM when using parameters that are not constrained to create an FSM


In the example below XST will see the tS0 up to tS3 as a 32-bit constant.

parameter tS0 = 0;

parameter tS1 = 1;

parameter tS2 = 2;

parameter tS3 = 3;

To avoid this problem, the code should be constrained as shown below.

parameter tS0 = 2'h0;

parameter tS1 = 2'h1;

parameter tS2 = 2'h2;

parameter tS3 = 2'h3;

For more information on the Coding Technique, please look at the link below:


AR# 23818
Date Created 09/04/2007
Last Updated 12/15/2012
Status Active
Type General Article