ch18_4字节不含正负符号的除法运算.asm

51单片机基础篇 对于有一定基础的人看看 包含书中所以的源代码

     ;FUNCTION NAME: DIV_4BYTE
     ;FUNCTION:UNSIGNED 4 BYTE DIVIDE
     ;(07H)(06H)(05H)(04H)=(07H)(06H)(05H)(04H)/(0FH)(0EH)(0DH)(0CH)
     ;WORKING AREA DATA MEMORY:(0BH),(0AH),(09H),(08H)
     ;
     DIV_4BYTE
           	LCALL 	CLEAR_INTERNAL_DATA_MEMORY
           	MOV   	R3,#32    	;SHIFT COUNT
           	CLR   	C
     $1    	MOV   	R1,#04H
           	MOV   	R2,#08H
     $2     	MOV  	A,@R1
           	RLC   	A
           	MOV   	@R1,A
           	INC   	R1
           	DJNZ 	R2,$2
           	MOV  	R0,#0BH
           	MOV   	R1,#0FH
           	MOV   	R2,#04H
           	LCALL	INTERNAL_DATA_COMPARE
           	JC   	$3
           	MOV  	R0,#08H
           	MOV   	R1,#0CH
           	LCALL	DATA_SUBTRACT
     $3    	CPL   	C
           	DJNZ  	R3,$1
           	MOV   	R1,#04H
           	MOV   	R2,#04H
     $4   	MOV   	A,@R1
           	RLC   	A
           	MOV   	@R1,A
           	INC   	R1
           	DJNZ  	R2,$4
           	RET