ASM cycles in PICBASIC

[Bruce]

Here's one version using a modified PBP library routine & macro;

Result VAR BYTE BANK0 SYSTEM
I      VAR BYTE BANK0 SYSTEM
Temp   VAR BYTE BANK0 SYSTEM
X      VAR BYTE

    TRISB.4 = 1
    Result = 0
    
Main:
    for I = 0 to 7       ' loop x 8
      X = 0
      while X < 10       ' Test pin x 10
        if PORTB.4 = 1 then
         call BitSet     ; Result.0[I] = 1
        else            
         call BitClear   ; Result.0[I] = 0
        endif
        X = X + 1 
      wend
    next I

Done:
    goto   Done
	
BitClear:
ASM
    call   ConvertBit  ; Bitmask -> W
    movwf  Temp        ; W -> Temp
    comf   Temp,F      ; Invert Temp
    movf   Temp,W      ; Temp -> W
    andwf  Result,F    ; AND W with Result
    return
ENDASM

BitSet:
ASM
    call   ConvertBit  ; Bitmask -> W
    iorwf  Result,F    ; OR W with Result
    return
    
;******************************************************
;* Input      : I = bit (0 - 7)                       *
;* Output     : W = bit mask                          *
;* Notes      : Modified example from PBP library     *
;******************************************************
ConvertBit              ; See pbppic14.lib CONVBIT & TABLE?C macro
    movlw   btable >> 8 ; Get high address of jump table
    movwf   PCLATH      ; Set program counter latch high
    movf    I,W         ; Get bit number from I into W reg
    andlw   07h         ; Isolate lower 3 bits (only works with 0-7)
    TABLE?C 08h         ; PBP library macro for table alignment
btable                  ; Returns from table with bit mask in W reg
    retlw   01h         ; %00000001
    retlw   02h         ; %00000010
    retlw   04h         ; %00000100
    retlw   08h         ; %00001000
    retlw   10h         ; %00010000
    retlw   20h         ; %00100000
    retlw   40h         ; %01000000
    retlw   80h         ; %10000000
ENDASM

    END

You can learn a good deal about assembly language by reading through the
PBP library.