In April, Randy Allen of Raytheon informed me that his latest compile of the FMF models had elicited an unexpected number of warning messages from the ModelSim 6.3f VHDL compiler. Although they were “only warnings” and the models still compiled and ran correctly, a large number of benign warnings can easy mask one that a user really cares about.
I upgraded my version ModelSim and did my own compile. It appears that ModelSim now flags as warnings departures from the VITAL LRM that it did not care about in earlier versions. Examination of the warning messages convinced me they were all valid. In many of our older models, we took some short cuts to speed development that have worked fine for the past 5 to 10 years. Now Mentor, most likely in their efforts to continually improve simulation performance, is suggesting stricter adherence to the standard. I assume what is a warning today could become a fatal error tomorrow.
In late April we began to fix the offending code. There were 50 or 60 models affected. To date, 14 corrected models have been posted. While this is not considered an urgent issue, it is FMF’s intention to updated all the flagged VHDL models over the course of the next few months. It is part of our commitment to delivery the highest quality product we can.