> -----Original Message-----
> From: Simon-Thijs de Feber [SMTP:stdf23173@YAHOO.CO.UK]
> Sent: Tuesday, April 09, 2002 7:01 AM
> To:   PICLIST@MITVMA.MIT.EDU
> Subject:      [PIC]:PWM
>
> Hello All,
>
> Yesterday evening i have been struggling with a PWM
> function.
>
> A char should be loaded with e.g. 0xF0, afterwards
> rotated right, and every passing LSB should be put on
> a output pin.
>
> So i did this in CC5x
>
> led1 = pwm.0;
> pwm = pwm >> 1;
>
> this generates something like
>
> BTFSS pwm,0
> BCF   led1
> BTFSC pwm,0
> BSF   led1
> CLR   0x05, C  //clear carry
> RRF   pwm,1
>
> The clear carry is not required cause i want a
> continues rolling function.
>
> So i removed the "clear carry" in an inline assembly
> block and included that in my code, but that has not
> solved the problem.
>
> any one an idea ?
>
Yes, you cannot expect the carry bit to contain the previous LSbit of the
pwm variable if you are performing any other operations that set/clear the
carry flag.

What you have to do is preload the carry bit with the LSbit like thisL

        rrf     pwm,w   ; move LSbit into carry, pwm unaffected
        rrf     pwm,f   ; rotate pwm, carry bit now moved to MSbit

Regards

Mike

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