Re: [Qemu-devel] [PATCH 11/22] i8259: Update IRQ state after reset

[Avi Kivity]

> >
> > It still has propagation delay.  If your XNOR gate connects to the
> > NORAD master launch controller, your design may have side effects.
>
> Hopefully the reset signal would control also the edge triggered
> launch controller.

It doesn't help.  There is propagation delay there as well.  If the input wins 
the race against reset, the launch sequence is started.

>
> The delays are one reason why real reset pulses are so long. The
> other
> reasons are the stabilization effects, internal and external.
>
> >> > We should either have just 1, or merge 1 and 2.
> >> >
> >>
> >> Then we'd be back to where the problems started.
> >>
> >
> > Sorry, I don't see the problem yet.
>
> I'm not sure we have a complete solution either. Phase 1 would solve
> most problems with old state which is the most important issue here.
> If the machine refuses to wake up from reset, this should be noticed
> quite soon, so we could move to dual phase system while still
> searching for the best possible system in all possible worlds.
>


Okay.  I still don't think there is a problem.