Re: [myhdl-list] myhdl.AlwaysCombError: signal (startmpy) used as inout in always_comb function argument

[Josy B. <jos...@gm...>]

Christopher Felton <chris.felton <at> gmail.com> writes:


> >>
> >> Why have a single comb vs. two comb?
> >
> > Because they target the same outputs. I'll augment the simplified
> > example a bit:
> 
> This modified code isn't a good example because the
> second state-machine always overwrites the first, so
> you can eliminate the first state-machines assignments
> to /Status/.

Yes, that's what happens with untested small example code. But you could 
assume that the **Status** was for monitoring (using SignalTap or some 
other method), it would me make wonder what happened '2' and '3' 

> 
> You would need states in each state-machine that doesn't
> assign and doesn't overlap - but ugh how do you keep
> track of that as the complexity grows?
> 
In this particular case, see https://github.com/josyb/KalmanFilter,  I 
could have added a third state machine which together would use the 
shared resource on an exclusive basis and the first state machine would 
only deal the cards. 

If the complexity would grow above this, I'd consider building a 
microprogrammed machine ;)

Best regards,

Josy