text2.asm

Philips单片机P89C51RD和西门子Profibus工业总线的接口程序,硬件是鼎实公司的实验板,使用的鼎实公司的总线桥.

 ORG      0000H
START:  MOV      R1,#00H
D:      DJNZ     R1,D
       MOV      SP,#60H
;
       MOV      P2,#00H
       CLR      P0.0
       MOV      P2,#01H
       CALL     DELAY
       MOV      P2,#00H
       SETB     P0.0
       MOV      P2,#01H
       CALL     DELAY 

;
DELAY:  MOV      R0,#00H
        MOV      R1,#00H
D1:     DJNZ     R1,D2
D2:     DJNZ     R0,D1
        RET

 end