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MOV SP,#70H
LOOP0: MOV 0CH, #00h ;除数低字节
MOV 0DH, #00h
MOV 0EH, #061h ;除数高字节
MOV 0FH, #0A8H
MOV 08H, #01H
MOV 09H, #0C9H
MOV 0AH, #0C3H
MOV 0BH, #080H
ACALL CHU40
RET
;4字节除4字节商为4字节除法子程序CHU40
;被除数放在内部08H.09H.0AH.0BH 单元中,除数放在0C.0D.0E.0F单元中
;商数放在内部R4.R5.R6.R7单元中,余数放在10H.11H.12H.13H单元中.
;溢出时商为零。余数为被除数
;资源影响;R0--16H共24字节 PSW 运行总时间1.977毫秒
CHU40: MOV R0, #20H
MOV 10H, #00H
MOV 11H, #00H
MOV 12H, #00H
MOV 13H, #00H
CHU47: CLR C
MOV A, 0BH
RLC A
MOV 0BH, A
MOV A, 0AH ;被除和扩充位左移
RLC A
MOV 0AH, A
MOV A, 09H
RLC A
MOV 09H, A
MOV A, 08H
RLC A
MOV 08H, A
MOV A, 13H
RLC A
MOV 13H, A
MOV A, 12H
RLC A
MOV 12H, A
MOV A, 11H
RLC A
MOV 11H, A
MOV A, 10H
RLC A
MOV 10H, A
MOV A, R7 ;商数左移
RLC A
MOV R7, A
MOV A, R6
RLC A
MOV R6, A
MOV A, R5
RLC A
MOV R5, A
MOV A, R4
RLC A
MOV R4, A
CLR C
MOV A, 13H ;判断
SUBB A, 0FH
MOV R1, A
MOV A, 12H ;判断
SUBB A, 0EH
MOV 14H, A
MOV A, 11H
SUBB A, 0DH
MOV 15H, A
MOV A, 10H ;判断
SUBB A, 0CH
MOV 16H, A
JC LOP490
INC R7
MOV 13H,R1 ;建立余数
MOV 12H,14H
MOV 11H,15H
MOV 10H,16H
LOP490: DJNZ R0, CHU47
RET
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