[Simulavr-devel] Re: AT43USB devices

[Theodore A. Roth]

On Mon, 6 Oct 2003, Keith Gudger wrote:

> Ted:
>
> (I tried to use the list, but the wonderful version of netscape on my Sun
> machine at Atmel won't let me....)

That's ok. I've replied to the list also.

>
> In trying to get the AT43USB3.. devices running in Simulavr, I found out
> that the file ports.c only knows about ports a,b,c,d.  These devices have
> ports e and f.  Are the only fixes for this in ports.c, *name_PIN,
> *name_DDR and *name_PORT?  If so, I'll make those changes in the next
> compile.

Probably better to add those as a second patch once the main USB dev
support is added. Note that the 103 and 128 among others could take
advantage of extending the number of possible ports.

>
> Also, the USB devices address the USB registers at SRAM addresses between
> 0x1fa0 and 0x1fff.  Is there a way to make this work in Simulavr?  Or does
> it mean major changes to your data structures and methods to add a 2nd
> discontinuous memory?  It would be nice to have, as the wonderful AVR
> Studios don't support this....

The current design for VDev's can't handle discontinuous memory. This
actually came up on the list in the last few weeks. I don't have a
solution for that yet. I'm busy with other projects right now, so I
haven't had a chance to dive into it.

>
> Also, as a gdb expert... Is there a way to force interrupts in gdb?  I
> haven't found any.

Someone else requested this a while back and I came up with a fairly
simple hack. Basically, since the avr targets don't understand signals
in the same sense as gdb (gdb uses the unix/posix point of view for
signals), I used gdb's 'signal' command to send a signal to the
target. This only requires a few minor changes to on the simulavr side
and no changes to gdb. To make things easier on the gdb side, the user
can define user commands in their .gdbinit file which give symbolic
names to the signal numbers. For example:

-- begin example .gdbinit --
define reset
  signal SIGHUP
end

define avr-irq-0
  signal 96+12
end
-- end example --

Don't take the 12 seriously, I pulled it out of the air. ;-)

Attached is the patch if anyone cares to test it. Whoever asked for it
originally never responded back so I let it slide. The patch might
need some tweaking to work with the current cvs though.

Ted Roth