spi从机.asm

关于ADUC841(51内核)的各种实验程序,有串口,ADC,DAC,PWM,的应用及基于ADUC841设计的万用表源程序

     $MOD841
      SP0    EQU   50H
      ORG    0000H
      LJMP   MAIN
      ORG    0003H
      LJMP   INT0_INT
      ORG    002BH
      LJMP   T2_INT
      ORG    003BH
      LJMP   SPI_INT
      ORG    0060H
MAIN:   MOV    R0,#0FFH
        CLR    A
QING:   MOV    @R0,A
        DJNZ   R0,QING
        MOV    SP,#SP0
        LCALL  YS
        LCALL  INI841
HERE:   LJMP   HERE
;----------------------------
INI841: SETB    EA
        SETB    ET2
        MOV     T2CON,#00H
        MOV     RCAP2H,#0D6H
        MOV     RCAP2L,#0B3H
        MOV     TH2,#0D6H
        MOV     TL2,#0B3H
        SETB    PT2
        MOV     IEIP2,#01H
        MOV     SPICON,#20H
        CLR     P1.5
        JB      P3.1,$
        CLR     P3.2
        RET
;------------------------
INT0_INT:CLR    SPE
         SETB   SPE
         SETB   P3.2
         RETI
;-------------------
SPI_INT: MOV    A,SPIDAT
         CJNE   A,#88H,OVER
         LCALL  SHENG_YIN
         SETB   P3.4
OVER:    RETI
;-------------------------
T2_INT:  CLR    TF2
         CPL    P3.4
         RETI
;-------------------------
SHENG_YIN:SETB   TR2
          LCALL  DELAY
          CLR    TR2
          RET
;---------------------------
DELAY:   MOV   R5,#150
D1:      MOV   R6,#150
D2:      MOV   R7,#150
         DJNZ  R7,$
         DJNZ  R6,D2
         DJNZ  R5,D1
         RET
;-----------------------------
YS:	MOV	R5,#00H
	MOV	R4,#50H
YS1:	DJNZ	R5,$
	DJNZ	R4,YS1
	RET
;------------------------------
        END