微机原理8251串口实验自发自收代码

8251

串口实验

自发自收

CODE    SEGMENT  

        ASSUME CS:CODE,DS:CODE,ES:CODE  

        ORG 35C0H               ;TX=RX  

H11:    JMP START  

Z8251   EQU 0FFE1H  

D8251   EQU 0FFE0H  

COM_MOD EQU 04EH  

COM_COM EQU 25H  

ZXK     EQU 0FFDCH  

ZWK     EQU 0FFDDH  

LED     DB 0C0H,0F9H,0A4H,0B0H,99H,92H,82H,0F8H,80H,90H  

        DB 88H,83H,0C6H,0A1H,86H,8EH,0FFH,0CH,0DEH,0F3H  

BUF     DB ?,?,?,?,?,?  

START:  MOV BX,0400H  

        MOV AL,[BX]  

        CMP AL,00H  

        JNZ SR0  

SR8251: MOV DX,Z8251  

        MOV AL,COM_MOD  

        OUT DX,AL  

        MOV AL,COM_COM  

        OUT DX,AL  

        MOV AL,01H  

        MOV BX,0400H  

        MOV [BX],AL  

SR0:    CALL WP  

        MOV SI,4000H  

        MOV DI,5000H  

        MOV CX,0010H  

SR1:    MOV AH,[SI]  

        CALL SEND  

        CALL RX  

        MOV [DI],AH  

        INC SI  

        INC DI  

        LOOP SR1  

SR2:    CALL DIS  

        JMP SR2  

RX:     MOV DX,Z8251  

RX1:    IN AL,DX  

        TEST AL,02H  

        JZ RX1  

        MOV DX,D8251