ljepson74 Posted March 11, 2014 Report Share Posted March 11, 2014 While I am waiting for an answer from the simulator vendor, I think I can form a non-tool-specific question about my problem. I am running a simulation which dies when I collect functional coverage. I can turn on/off functional coverage collection and when it is on, at the very end of simulation, I get: "ncsim: *F,INTERR: INTERNAL EXCEPTION". It seems to be that while coverage is gathered, the problem occurs. I can run tests which flow thru some channels of the dut and don't have the problem, but thru a specific channel of the dut, I often encounter the problem. question1: What is classified as functional coverage? I'd like to leave functional coverage collection on and comment out all coverpoints/covergroups. (Actually I think I have, or am close, and the error still occurs.) So, I am wondering, what must I grep for to remove to be sure that functional coverage collection has no meaning? My thought is to divide and conquer. Am I not just looking for "coverpoint" and "covergroup", but also "assert" (as some code might have assertion based functional coverage)? Is there anything else? question2: (This is perhaps a bit tool specific.) If the -covdut, or scope of where coverage should be gathered is targetted to a sub-sub-module, would you expect that (possibly bad) coverage code at a higher level (or different area) would have zero affect on the coverage collection? (I've unsuccessfully tried to leave functional coverage collection on, but to move the target-scope to a trival part of the design, to see if the problem goes away.) Hermanmeds 1 Quote Link to comment Share on other sites More sharing options...
apfitch Posted March 12, 2014 Report Share Posted March 12, 2014 Assertions count as functional coverage (at least according to section 16.2 of 1800-2012). You can disable all assertions with $assertoff. Otherwise "it's probably a tool issue". I don't have any other ideas re your question 2. regards Alan Quote Link to comment Share on other sites More sharing options...
ljepson74 Posted March 24, 2014 Author Report Share Posted March 24, 2014 Thanks, Alan. This did turn out to be a tool issue. (When collecting coverage at the end of the test the crash happened. If we stepped thru the code and periodically collected coverage at a few points in the sim, including the end, there was no problem.) An update to the next/latest patch fixed this. regarding 1,2 1. Note to self: it seems functional coverage is specified by coverpoints and some assertions (depends upon how used) An AE showed me a Cadence commandline option, -covcglog, to see what code the tool is considering as functional coverage. I haven't explored it much yet though. 2. While I'd like to explore this more to find out what functional coverage item prompted the problem/coverage-collection-crash (if it could be tied to a specific one), I must move on with other tasks. Quote Link to comment Share on other sites More sharing options...
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