MUL2BY2:CLR A
MOV R7,A
MOV R6,A
MOV R5,A
MOV R4,A
MOV 46H,#10H
MULLOOP1:CLR C
MOV A,R4
RLC A
MOV R4,A
MOV A,R5
RLC A
MOV R5,A
MOV A,R6
RLC A
MOV R6,A
MOV A,R7
RLC A
MOV R7,A
MOV A,R0
RLC A
MOV R0,A
MOV A,R1
RLC A
MOV R1,A
JNC MULLOOP2
MOV A,R4
ADD A,R2
MOV R4,A
MOV A,R5
ADDC A,R3
MOV R5,A
MOV A,R6
ADDC A,#00H
MOV R6,A
MOV A,R7
ADDC A,#00H
MOV R7,A
MULLOOP2:DJNZ 46H,MULLOOP1
RET
DIV4BY2:MOV 46H,#20H
MOV R0,#00H
MOV R1,#00H
DIVLOOP1:MOV A,R4
RLC A
MOV R4,A
MOV A,R5
RLC A
MOV R5,A
MOV A,R6
RLC A
MOV R6,A
MOV A,R7
RLC A
MOV R7,A
MOV A,R0
RLC A
MOV R0,A
MOV A,R1
RLC A
MOV R1,A
CLR C
MOV A,R0
SUBB A,R3
JC DIVLOOP2
MOV R0,B
MOV R1,A
DIVLOOP2:CPL C
DJNZ 46H,DIVLOOP1
MOV A,R4
RLC A
MOV R4,A
MOV A,R5
RLC A
MOV R5,A
MOV A,R6
RLC A
MOV R6,A
MOV A,R7
RLC A
MOV R7,A
RET
END <PIXTEL_MMI_EBOOK_2005>9 </PIXTEL_MMI_EBOOK_2005>
来源:仪表技术