Variable Registers...

R

Rick C

Guest
I typically don\'t use variables much, but I like the limited scope which means fewer \"global\" signals cluttering up the declaration portion of an entity. But they can be a bit tricky to use because of the nature of the assignments.

I was just sculpting a section of code that used a couple of down counters as variables and kept finding myself altering the value before I checked it.. To work around that I had to do multiple assignments in multiple branches of IFs. Using a signal I would have made one assignment at the top of the section of code, the default case, then one other assignment in a single branch of the IFs. Since the counter value was in the first conditional that could not be done with a variable as it would be examining the updated value.

In the end I had to use three assignments instead of two more clear ones to avoid the signal declaration.

Signals are also easier to show in the waveform display during simulation as I can throw up everything in the entity in one click. The variables require a little more work.

Not sure I have a question, just a comment really.

--

Rick C.

- Get 1,000 miles of free Supercharging
- Tesla referral code - https://ts.la/richard11209
 

Welcome to EDABoard.com

Sponsor

Back
Top