AVR-Chat

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
> 
> 
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