Re: [Simulavr-devel] two things

[Theodore A. Roth]

On Wed, 19 Nov 2003, John Regehr wrote:

> There's a mistake in devsupp.c:296, I think.  The ATmega103 has only 4000
> bytes of SRAM, not 4096.  The manual says "4 KB" of SRAM a few times but
> that's not quite right: it actually lives at addresses 0x60-0xfff.

That definitely needs fixing. I've already made the change in my tree and 
will commit to cvs shortly.

> 
> Has anyone looked into a portable way to tie interrupts to their enable
> bits?  I was thinking this could be done by extending struct _IntVect to
> include an I/O location and a bit number, providing a portable way for the
> interrupt logic to decide when an interrupt should fire.  So the _IntVect
> for TWI on an ATmega128 would become { "IRQ_TWI", 0x42, 0x00, 0x74, 0 }.
> I'm interested in the interrupt bits because I need to support these in an
> AVR binary analysis tool I'm writing.  It seems reasonable to share this
> code with simulavr if people are interested.

What actually causes the interupt to fire may not even be related to the 
register that contains the intr enable bit.

Can you expand on your idea a bit? How do you envision the extra info 
helping simulavr fire off an interrupt?

I'm interested in where you are going with this.

Ted Roth