he10.asm

51系列单片机的汇编程序包

;===================== 硬件实验十  D/A输出方波 =========================
;注意：进行本实验前，请先装载运行D/A 0V输出（调基准电压）程序Asm51\da_0v.asm
;　　　使D/A输出端“AOUT”输出电压为0V，再进行本实验。

        ORG 061FH
        MOV SP,#53H
        MOV 7EH,#00H
        MOV 7DH,#08H
        MOV 7CH,#03H
        MOV 7BH,#02H            ;显示缓冲区初值
LO23:   MOV A,#80H
        CALL LO21
        MOV A,#0FFH
        CALL LO21
        SJMP LO23
;---------------------------
LO21:   MOV DPTR,#0FFE0H
        MOVX @DPTR,A            ;送0832转换
        MOV R0,#79H
        CALL PTDS
LO2Z:   MOV R2,#20H
L023:   CALL DIS               ;显示
        DJNZ R2,L023
        RET
;---------------------------
PTDS:   MOV R1,A                ;拆送显示缓冲区
        ACALL PTDS1
        MOV A,R1
        SWAP A
PTDS1:  ANL A,#0FH
        MOV @R0,A
        INC R0
        RET
;-----------------------------
DIS:    PUSH DPH
        PUSH DPL
        SETB RS1
        MOV R0,#7EH
        MOV R2,#20H
        MOV R3,#00H
        MOV DPTR,#LS0
LS2:    MOV A,@R0
        MOVC A,@A+DPTR
        MOV R1,#0DCH
        MOVX @R1,A
        MOV A,R2
        inc R1
        MOVX @R1,A
LS1:    DJNZ R3,LS1
        CLR C
        RRC A
        MOV R2,A
        DEC R0
        JNZ LS2
        movx @r0,a
        dec r0
        cpl a
        movx @r0,a
        CLR RS1
        POP DPL
        POP DPH
        RET
;---------------------------------
LS0:    DB 0C0H,0F9H,0A4H,0B0H,99H,92H
        DB 82H,0F8H,80H,90H,88H,83H,0C6H
        DB 0A1H,86H,8EH,0FFH,0CH,89H,7FH,0BFH
;-------------------------------
        END