soufa.asm

早期开发的MS8051与PC的RS232通讯-1程序源码

;_____________	串行通信模块  _______________
;
	org	00h
	ajmp	start
        org     0003h
        ajmp    INT0
        org     0013h
        lcall   0ff77h
        ORG     0023H
        ajmp    shou
        org     0030h
start:  mov     SCON,#50H
	mov	tmod,#20h		;设定时器1为波特率发生器
	mov	th1,#0f1h
	mov	tl1,#0f1h		;波特率1200
        MOV     IP,#18h
        mov     ie,#98h
        clr     ti
        clr     ri
hear:   ajmp    hear
int0:   cpl     p1.0
        mov     r6,#08h
        mov     r1,#30h
loop1:  mov     r7,#7fh
lop1:   djnz    r7,lop1
        setb    tr1
        nop
loop:   mov     a,@r1
        mov     sbuf,a
        jnb     ti $
        clr     ti
        inc     r1
        djnz    r6,loop
        clr     tr1
loop2:  mov     ie,#98h
        mov     r7,#0fh
lop2:   djnz    r7,lop2
        clr     ie0
        ajmp    hear
        nop
shou:   mov     r1,#20h
        mov     r4,#08
shou1:  mov     a,sbuf
        mov     @r1,a
        inc     r1
        clr     ri
        jnb     ri $
        djnz    r4,shou1
        clr     ri
        reti
	end
;