07-06-2017 11:16 AM
07-06-2017 01:02 PM
Simulation models for complex behaviors may not be accurate.
Simply put, the model is intended to show functionality, but is not the actual circuitry.
In later families, the models are better, but some are still not perfect (matching exactly actual behavior).
07-06-2017 01:21 PM
Thanks for the reply Austin.
I understand your point about simulation models.
So does that mean my model can't be truly verified in simulation and my model might have a bug that causes the maximum number of steps that I count to be above 255?
Even if that may be, how come that on hardware the overflow bit sometimes vibrates?
07-06-2017 01:27 PM
The silicon is what exists, and thus, what you see is real. I would stay within the operating "rules" and not rely on overflow being an exact value (like 255) which it will not be. Rather, I used a separate counter to mirror the counter in the DCM when I needed to "know" the count, so I could take action. At least, that is what I did years ago now when I faced a similar issue.