1.4.2 多字节无符号数除法.txt

数值算法,C51单片机的汇编程序

DODIV:		
MOV	A,R0					
MOV	R4, A
MOV	A, R1				
MOV	R5, A
MOV	A, R3				
MOV	R7, A
MOV	A, R0
ADD		A, R3
MOV	R6,A					
MOV	R1, A
LP0:		
MOV	@R1,#00H				
INC		R1
DJNZ	R3, LP0
MOV	A,R7					
ADD		A, R7
MOV	R2, A
MOV	B, #04H
MUL		AB					
LP1:		
PUSH	A					
MOV	A, R2
MOV	R3, A
MOV	A, R4
MOV	R1, A
CLR		C					
LP2:		
MOV	A,@R1				
RLC		A					
MOV	@R1, A
INC		R1					
DJNZ	R3, LP2
NEXT:		
MOV	A, R6				 
MOV	R0, A
MOV	A, R5				
MOV	R1, A
MOV	A, R7
MOV	R3, A				
CLR		C
LP3:		
MOV	A,@R0				
SUBB	A,@R1
PUSH	A
INC		R0					
INC		R1					
DJNZ	R3, LP3
MOV	A, R7
MOV	R3, A
JC		SMALL				
MOV	A, R4
MOV	R0, A
INC		@R0					
MOV	A, R6
ADD		A, R7
DEC		A
MOV	R0, A
LP4:		
POP		A					
MOV	@R0, A
DEC		R0
DJNZ	R3, LP4
SJMP	NEXT
SMALL:		
POP		A					
DJNZ	R3, SMALL
POP		A
DEC		A				  
JNZ		LP1
I504:		
MOV	A,R6					
ADD		A, R7
DEC		A					
MOV	R0, A
MOV	R2, A
MOV	A,@R0
JB		E7H, ADD1
MOV	A, R6
MOV	R1, A
MOV	A, R7
MOV	R3, A
CLR		C					
LP5:		
MOV	A,@R1
RLC		A					
MOV	@R1, A
INC		R1					
DJNZ	R3, LP5
MOV	A, R2
MOV	R0, A
MOV	A, R7
MOV	R3, A
ADD		A, R5
DEC		A					
MOV	R1, A
LP6:		
CLR		C
MOV	A,@R0
SUBB	A,@R1
JC		RETURN				
JNZ		ADD1
DEC		R0					
DEC							
DJNZ	R3, LP6
ADD1:		
MOV	A,R4					
MOV	R1, A
MOV	A, R7
MOV	R3, A
SETB	C					
LP7l:
MOV	A,@R1
ADDC	A, #00H
MOV	@R1, A
DJNZ	R3, LP7
RETURN:	
MOV	A,R4					
MOV	R0, A
MOV	A, R7
MOV	R3, A
RET