#30 latch coverage
This is also likely an addition that you don't have time for, but is there any way to get covered to recognize and not ignore latches?
In my current design I have a huge number of intended set/reset latches. In some places I can change these to flip-flops with a define for coverage analysis, but for other places the latch is integral to the functionality of the circuit. I use it to prevent glitching during part of a calculation, but other calculation paths need to propagate immediately. Basically I have a nominal value and a correction that are added together. Any change in the nominal value needs to propagate immediately. but the correction is performed during operation where there are critical timing constraints on when values can change so the new value is calculated while the previous value is latched. At the appropriate time the new value is passed by making the latch transparent. This removes glitching and helps align the bit changes in time.
The attached example demonstrates how I code the latches. The run script should be the same as previous examples.
Any suggestions would be appreciated.
Discussion
Anonymous
example of latches
Cary,
If you use the -rI option to the score command, Covered will not ignore these logic blocks. You can, alternatively, use the -rP option and place "// racecheck off" .. "// racecheck on" around these blocks if you want Covered to still perform static race condition checking on the rest of the design, but -rI is the bigger hammer and might be more desirable in your instance.
Trevor
OK, I'll try that and see how things go.
Thanks,
Cary
That worked. I guess you can switch this to a feature request to keep the bug report space cleaner.