Seth Fischer wrote:

> What does it mean to rotate a file _through the carry bit_ (RLF and
> RRF)?
>

to determine when it will pass over  0xFF.

> When executing RLF on portB (8 LEDs) I get this:
>
> portB = 00000001
>         RLF     portb
> portB = 00000011        ; I want only one bit high and 'walking' left
>         RLF     portB
> portB = 00000110
>         RLF     portB
> portB = 00001100
>
> What is happening?
>

did you clear portb and w before setting bit 0 high ?

>
>
> Seth Fischer
> Auckland, New Zealand


Andre Abelian