AVR-Chat

Toggling a pin by writing to the PIN register works on most of the NEWER 
processors, but not all of them.
  Does work on m48/88/168.
  It's a neat trick. It is documented, but you have to be looking for it.

-carl

At 12:33 PM 6/12/2005, you wrote:
>Hello,
>
>You may be able to toggle a port bit by writing a 1 to the corresponding
>PINx bit. I've not seen it documented anywhere except in the m2560 document.
>You might want to try it to see if it works on all AVR processors.
>
>For PORTn and BITx it would be, I think...
>
>tgl_bit: sbi PINn,BITx
>ret
>
>Jim
>
>----- Original Message -----
>From: "Mark Jordan" <mark@cpovo.net>
>To: <AVR-Chat@yahoogroups.com>
>Sent: Sunday, June 12, 2005 5:55 AM
>Subject: Re: [AVR-Chat] Bit logic...
>
>
> >
> > Another way of toggling a PORT bit:
> >
> >
> > tgl_bit: sbis PORTC, BIT
> > rjmp sbi_bit
> >
> > clr_bit: cbi PORTC, BIT
> > ret
> >
> > set_bit: sbi PORTC, BIT
> > ret
> >
> >
> > Mark
> > On 12 Jun 2005 at 1:58, Roy E. Burrage wrote:
> >
> > >
> > > I often have to toggle a bit and this is about as short and elegant as
>I've been
> > > able to do with the AVR.
> > >
> > >
> > >  Toggle_A1:             ; Toggles PB0 (A1) output state
> > >      LDI  T1,1     ; Set bit 0 in T1
> > >       IN   T2,PORTB
> > >      EOR  T2,T1      ; XOR T1 and Port B (T2) to toggle PB0
> > >      OUT  PORTB,T2
> > >      RET
> > >
> > > This routine is called from the main program and could be performed a
>couple of
> > > other ways, but not anything shorter that I can see.
> > >
> > > With the 8x31/32 series we had the CPL operation. With the er, uh, those
>other
> > > guys...we have BTG.
> > >
> > > Anyone know of a shorter means, code wise, of doing this? Am I missing
> > > something, like a single operation?
> > >
> > >
> > > REB
> > >
> > >