;Division d'un binaire 32bits/16bits
;Entrée dividende R3:R2:R1:R0
;Entrée diviseur R21:R20
;Sortie résultat R3:R2:R1:R0
;Reste R7:R6:R5:R4
; .DEF 	a0 = R0            ;Octet bas dividende/réponse
; .DEF 	a1 = R1            ;To hold second-byte of answer
; .DEF 	a2 = R2            ;To hold third-byte of answer
; .DEF 	a3 = R3            ;To hold fourth-byte of answer     

; .DEF 	b0 = R4            ;Octet bas du reste
; .DEF 	b1 = R5            ;To hold second-byte of remainder
; .DEF 	b2 = R6            ;To hold third-byte of remainder
; .DEF 	b3 = R7            ;To hold fourth-byte of remainder

; .DEF 	buffer = R8        ;To hold the value Zéro
; .def	count=R17			;Bit Counter
; .DEF   A = R16           ;registre général

 .DEF   BL = R21           ;Octet bas du diviseur
 .DEF   BM = R22               
 .DEF	BH = R23			;To hold high-byte of divisor

        ; LDI A,LOW(420)   ;Load low-byte of dividend into A1
		; mov a0,A
        ; LDI A,BYTE2(420) ;Load second-byte of dividend into A2
		; mov a1,A
        ; LDI A,BYTE3(420) ;Load third-byte of dividend into A3
		; mov a2,A
        ; LDI A,BYTE4(420) ;Load fourth-byte of dividend into A4
		; mov a3,A
        
        ; LDI BL,LOW(10)    ;Load low-byte of divisor into BL
        ; LDI BH,HIGH(10)   ;Load high-byte of divisor into BH

DIV3224:
        CLR buffer
        ;MOVW a1:a0,A2:A1 ;Copy dividend into answer
        ;MOVW a3:a2,A4:A3 ;
        LDI count,33          ;Load bit counter
        SUB b0,b0     	;Clear Remainder and Carry
        CLR b1          ;
        CLR b2          ;
        CLR b3          ;
LOOP:   ROL a0          ;Shift the answer to the left
        ROL a1          ;
        ROL a2          ;
        ROL a3          ;
        DEC count             ;Decrement Counter
        BREQ DONE        ;Exit if 32 bits done
        ROL b0          ;Shift remainder to the left
        ROL b1          ;
        ROL b2          ;
        ROL b3          ;
        SUB b0,BL       ;Try to subtract divisor from remainder
        SBC b1,BM       ;
        SBC b2,BH     ;
        SBC b3,buffer     ;
        BRCC SKIP        ;If the result was negative then
        ADD b0,BL       ;reverse the subtraction to try again
        ADC b1,BM       ;
        ADC b2,BH     ;
        ADC b3,buffer     ;
        CLC               ;Clear Carry Flag so buffer shifted into A 
        RJMP LOOP        ;Loop Back
SKIP:   SEC               ;Set Carry Flag to be shifted into A
        RJMP LOOP
DONE:	ret