Carter Brock wrote:

> The problem is I have 76 bits in 8 consecutive bytes that have been
> interleaved in the following pattern:

It's real big problem because 76 bits overflow 8 bytes ;)
I think you are talk about 9.5 bytes ?

> (1,20,39,58,2,21,40,59....)
So you have sequence above and you need to rearrange it
to 1,2,3,4,5,....,73,74,75,76 ?

I think it will be easy read bit by bit sequency from input
to fill 4 3-bytes arrays like example below .

; bytes A0 | A1 | A2 = x,x,x,x,x,1,2,3 | 4,5,6,7,8,9,10,11 |
12,13,14,15,16,17,18,19
; B0 | B1 | B2 = x,x,x,x,x,20,21,22 | 23,24,25,26,27,28,29,30 |
31,32,33,34,35,36,37,38
; C0 | C1 | C2 = x,x,x,x,x,39,40,41 | 42,43,44,45,46,47,48,49 |
50,51,52,53,54,55,56,57
; D0 | D1 | D2 = x,x,x,x,x,58,59,60 | 61,62,63,64,65,66,67,68 |
69,70,71,72,73,74,75,76

;Let suppose you read from port PORT from input pin with number IN_BIT

PORT    EQU     PORTC
IN_BIT  EQU     5       ;PORTC.5

        MOVLW   D'19'
        MOVWF   COUNT

READ_LOOP:
        MOVFW   PORT,IN_BIT     ;copy IN_BIT to Carry
        ANDLW   (1<<IN_BIT)
        ADDWF   ~(1<<IN_BIT)+1
        RLF     A2              ;shift Carry to A
        RLF     A1
        RLF     A0

        MOVFW   PORT,IN_BIT     ;read IN_BIT to Carry
        ANDLW   (1<<IN_BIT)
        ADDWF   ~(1<<IN_BIT)+1
        RLF     B2              ;shift Carry to B
        RLF     B1
        RLF     B0

....
....
;       Also read to C0,C1,C2 and D0,D1,D2
....
....
        DECFSZ  COUNT
        GOTO    READ_LOOP



> Now if there was such an animal in the PIC world as a bit array, code that
> looked something like this would do it:
>
> for (i=0;i<20,i++) {
>   for(j=0;j<3;j++) {
>     deinterleaved_array[k++]=interleaved_array[(j*19)+i];

?????                                             ^^^^
      deinterleaved_array[k++]=interleaved_array[(j*4)+i];

>   }
> }
>
> Any suggestions on the best way of testing, setting and clearing bits in an
> array of bytes?
>
>                         TIA,
>
>                                 Carter Brock


WBR Dmitry.