实验五 D/A转换实验

1. 实验内容

基础部分

编写程序，产生周期的锯齿波、矩形波、三角波和阶梯波，经 D/A 转换，显示在软件模拟示波器上。
要求：每种波形的周期数、阶梯波的阶梯数可通过参数设置。

扩展部分

在软件模拟示波器上显示锯齿波、矩形波、三角波和阶梯波，并使用单脉冲开关KK1在四种波形间进行切换。

2. 实验原理

3. 连线

KK1 连接 MIR6

4. 实验代码

基础部分：

（见扩展部分）

扩展部分：

DAC0832 EQU 0600H

DATA SEGMENT
    SIGN DB 00H  
DATA ENDS

CODE SEGMENT
    ASSUME  CS:CODE, DS:DATA
START:
    MOV AX, 0000H        
    MOV DS, AX

    LEA AX, MIR6
    MOV SI, 38H
    MOV [ES:SI], AX
    MOV AX, CS
    MOV SI, 3AH
    MOV [ES:SI], AX

    CLI
    MOV AL, 11H
    OUT 20H, AL
    MOV AL, 08H
    OUT 21H, AL
    MOV AL, 04H
    OUT 21H, AL
    MOV AL, 07H
    OUT 21H, AL
    MOV AL, 2FH
    OUT 21H, AL
    STI

MAIN:
    CMP SIGN, 0
    JZ SAW
    CMP SIGN, 1
    JZ REC
    CMP SIGN, 2
    JZ TRI
    CMP SIGN, 3
    JZ STA_CON
    JMP MAIN

SAW:
    CMP SIGN, 0
    JNE MAIN
    MOV DX, DAC0832
    MOV AL, 00H
SA1: 
    OUT DX, AL
    CALL DELAY1
    CMP AL, 0FFH
    JE  SA2              

    INC AL
    JMP SA1
SA2:
    JMP SAW

REC:
    CMP SIGN,1
    JNE MAIN
    MOV DX, DAC0832
    MOV AL, 00H
    OUT DX, AL
    CALL DELAY2
    MOV AL, 0FFH
    OUT DX, AL
    CALL DELAY2
    JMP REC
STA_CON:  
    JMP STA
STA_RET:  
    JMP MAIN

TRI:
T1:
    CMP SIGN, 2
    JNE MAIN
    MOV DX, DAC0832
    OUT DX, AL

    CALL DELAY1
    CMP AL, 0FFH
    JE T2           
    INC AL
    JMP T1
T2:
    MOV DX, DAC0832
    OUT DX, AL
    CALL DELAY1
    CMP AL, 00H
    JE T3     
    DEC AL
    JMP T2
T3:
    JMP TRI

STA:
    MOV AX, 0FEH
    MOV BL, 05H 
    DIV BL
    MOV BL, AL
    MOV BH, 00H
ST1:
    CMP SIGN,3
    JNE STA_RET
    MOV AX, 0000H
ST2:
    MOV DX, DAC0832
    OUT DX, AL
    CMP AX, 00FFH
    JAE ST3
    CALL DELAY2
    ADD AX, BX
    JMP ST2
ST3:    
    JMP STA

MIR6:
    INC SIGN
    CMP SIGN, 4
    JNZ QUIT
    MOV SIGN, 0
QUIT:
    IRET

DELAY1:
    PUSH CX
    MOV CX, 01FFH
D1: PUSH AX
    POP AX
    LOOP D1
    POP CX
    RET

DELAY2:
    PUSH CX
    MOV CX, 0FFFFH
D2: PUSH AX
    POP AX
    LOOP D2
    POP CX
    RET

CODE ENDS
    END START