32 bits by 16 by Peter Hemsley
divide movlw 32
divide movlw 32
| CODE |
| ; 32-bit divide by 16-bit movwf bitcnt clrf remdrH ; Clear remainder clrf remdrL dvloop clrc ; Set quotient bit to 0 ; Shift left dividend and quotient rlf divid0 ; lsb rlf divid1 rlf divid2 rlf divid3 ; lsb into carry rlf remdrL ; and then into partial remainder rlf remdrH skpnc ; Check for overflow goto subd movfw divisH ; Compare partial remainder and divisor subwf remdrH,w skpz goto testgt ; Not equal so test if remdrH is greater movfw divisL ; High bytes are equal, compare low bytes subwf remdrL,w testgt skpc ; Carry set if remdr >= divis goto remrlt subd movfw divisL ; Subtract divisor from partial remainder subwf remdrL skpc ; Test for borrow decf remdrH ; Subtract borrow movfw divisH subwf remdrH bsf divid0,0 ; Set quotient bit to 1 ; Quotient replaces dividend which is lost remrlt decfsz bitcnt goto dvloop return |
Comments:
| QUOTE |
| It wouldn't hurt to change "movlw 32" to "movlw .32" (without quotes). If default radix isn't decimal, assembler will misinterpret that number... |