Hi Jinx,

PWM_DIFF and then also PWM_Temp wil change before entering the
subroutine.
It wil change from 0x00 to 0xFF

Harry 

> -----Oorspronkelijk bericht-----
> Van: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] 
> Namens Jinx
> Verzonden: zondag 11 januari 2009 23:48
> Aan: Microcontroller discussion list - Public.
> Onderwerp: Re: [PIC] Preapering CCP1CON register for PWM
> 
> > ;                         CCP1CON  = 0b 0111 1100
> 
> > ; At this point the value of CCP1_Temp = 0b 0001 0000
> 
> > ;    iorlw    b'11001111'
> > ;    iorwf   CCP1CON, f           ; Mask with the changes
> 
> > ; And CCP1CON should become 0b0101 1100
> 
> >     movwf   CCP1CON             ; and rewrite the new value
> 
> Harry, it seems to me that CCP1CON will never change from
> 0111 1100 to 0101 1100. The bit you want to change, bit5, 
> doesn't appear in the CCP1_Temp mask
> 
>     rrf     CCP1_Temp           ; Do this always to
>     rrf     CCP1_Temp           ; prepare the CCP!CON mask
>     rrf     CCP1_Temp           ; afterwards
> 
> Too far ?
> 
> What would help are comments explaining why the instructions 
> are used, and in detail what the function of the routine is. 
> For example, in these three lines, I can see what's 
> happening, but don't know why
> 
>     bcf     STATUS, C           ; Clear C flag
>     rrf     PWM_Temp            ; Move LSB:0 out
>     rrf     CCP1_Temp           ; And save it
> 
> As for the banking, according to the .inc file all of those 
> CCP registers are in bank 0, so as long as you're entering 
> the routine in bank0 that should be OK
> 
> 

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