i am working with imc coverage tool for ip coverage.
certain if-elsif conditions are not covered even if i write various test patterns for it. even if i write all combinations in a testpattern for those specific condition, the tool reports some combinations as uncovered. Help/suggestions awaited!
Without seeing your uncovered code, and your coverage scoring options, it's not possible to say for sure. However I would suspect that it may be due to the way expressions are covered by default. Short-circuit evaluation means that the first part of the expression that determines its value will be the one that gets scored, and any subsequent terms are never executed or scored. This is following the normal HDL language rules. Look in the documentation ("cdnshelp" tool) at the information about short-circuit evaluation in the ICC User Guide.
You can try searching for set_expr_scoring in the docs to get quickly to the relevant control options.
I used the command set_expr_scoring -no_vhdl_shortcircuit in the coverage config file and it worked as required. But then too atleast one combination remains uncovered always.
Kindly Suggest on it.
OK, I'm glad that helped. Regarding the remaining combinations that are not covered, I can't offer any explanation since you didn't post any example of your code.
I understand that you may not want to share it in a public forum, so I would recommend that you go to http://support.cadence.com/ and file a service request. You can safely exchange more detailed info about your design with the Cadence support engineers and they will be able to explain the appropriate settings based on your exact issue.
We can always post the solution back here in the forum for others to see once we know the details...