Return from subroutine not working on PIC18

Question

I'm writing a subroutine to count the number of set bits in wreg, but on reaching the return statement at the end of the subprogram it just repeats the return statement endlessly. I'm new to PIC and assembly, so I'm sure I've just done something silly, but I haven't been able to work it out yet. Any help would be greatly appreciated.

Here is my code:

COUNT       equ 0x00

NUMBER      equ 0x01

BITS        equ 0x02

;bitcounter subprogram counts the number of set bits in a byte

BITCOUNTER:

Loop1   rlcf NUMBER,f   ;rotates one bit of number into carry flag, store rotated number

    btfsc STATUS, C     ;skips next line if carry is clear

    incf COUNT, f   ;add one to count, store in count

    bcf STATUS, C   ;clear carry flag

    decfsz BITS

    goto Loop1

    movf COUNT, 0   ; put bit count into W register
return 

START

        movlw   0x0008

        movwf   BITS

        movlw   0xF2

        movwf NUMBER    ;stores input as "number"

        call BITCOUNTER

    end

Answer 1

I'm new to PIC programming and haven't uploaded any codes to PICs as of yet (still waiting for programmer delivery) but I think that the "goto start" at the end fixes the problem because a PIC needs to do something. The "goto start" instruction puts the PIC in a loop so it doesn't have to try and "stop". In it's absence, I think that the PIC is trying to deal with the "not being able to stop" by simply repeating the last instruction indefinitely.

If so, you could alternatively add something like (assuming I have set it out right):

loop2 nop
      goto loop2

at the end of your code. The PIC would continue to run a no-operation until you reset it (or you could set up an interrupt, WDT or some other function as required).