51单片机汇编程序集(3)

      NDV414   :XCH    A,R5
                 MOV     R7,A
                RET
      ;双字节无符号除法程序 (R5R2R3R4/R6R7)=(R2)R3R4 余数R6R7
      ;入口    :R5,R2,R3,R4,R6,R7
      ;占用资源:ACC,B,F0
      ;堆栈需求:4字节
      ;出口    :(R2),R3,R4,R6,R7,OV
      NDIV42   : MOV     A,R1
                PUSH   A
                 MOV     B,#00H
      NDV421   : MOV     A,R2
                CLR    C
                SUBB   A,R7
                 MOV     R1,A
                 MOV     A,R5
                SUBB   A,R6
                JC     NDV422
                 MOV     R5,A
                 MOV     A,R1
                 MOV     R2,A
                INC    B
                SJMP   NDV421
      NDV422   :PUSH   B
                 MOV     B,#10H
      NDV423   :CLR    C
                 MOV     A,R4
                RLC    A
                 MOV     R4,A
                 MOV     A,R3
                RLC    A
                 MOV     R3,A
                 MOV     A,R2
                RLC    A
                 MOV     R2,A
                XCH    A,R5
                RLC    A
                XCH    A,R5
                 MOV     F0,C
                CLR    C
                SUBB   A,R7
                 MOV     R1,A
                 MOV     A,R5
                SUBB   A,R6
                JB     F0,NCV424
                JC     NDV425
      NCV424   : MOV     R5,A
                 MOV     A,R1
                 MOV     R2,A
                INC    R4
      NDV425   :DJNZ   B,NDV423
                POP    A
                CLR    OV
                JNZ    NDV426
                SETB   OV
      NDV426   :XCH    A,R2
                 MOV     R7,A
                 MOV     A,R5
                 MOV     R6,A
                POP    A
                 MOV     R1,A
                RET
      ;N字节无符号除法程序(组合) ([R0]/[R1])=([R0])
      ;入口    :R0,R1,M,N
      ;占用资源:ACC,R2,R3,R4,R5,R7,NCNT,F0,NADDN,NSUBBN,NRLCN

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本文关键字：单片机  51单片机，单片机-工控设备 - 51单片机