单片机汇编语言基于AT89C52和DAC0808按键控制和电压输出显示的多档数字调压器设计 举例Keil4汇编语言程序

以下是基于AT89C52和DAC0808按键控制和电压输出显示的多档数字调压器的Keil4汇编语言程序：

; AT89C52 DAC0808 Digital Voltage Regulator
; Author: Your Name
; Date: 2021/01/01

; Define the MCU clock frequency
$CRYSTAL equ 11059200
$BAUD equ 9600

; Define the DAC0808 control pins
CS equ P1.0
WR equ P1.1
ADR equ P1.2

; Define the key control pins
K1 equ P2.0
K2 equ P2.1

; Define the voltage output pins
VOUT1 equ P0.0
VOUT2 equ P0.1

; Define the voltage levels
V1 equ 1.0
V2 equ 1.5
V3 equ 2.0
V4 equ 2.5
V5 equ 3.0

; Define the initial voltage level
LEVEL equ V1

; Define the delay time
DELAY equ 500

; Define the main program
ORG 0000h

START:
    ; Initialize the MCU
    MOV SP, #07h
    MOV P1, #00h
    MOV P2, #FFh
    MOV P0, #00h

    ; Set the timer interrupt
    MOV TMOD, #01h
    MOV TH0, #0FEh
    MOV TL0, #0CCh
    SETB TR0
    SETB ET0
    SETB EA

    ; Set the serial port baud rate
    MOV SCON, #50h
    MOV TH1, #-3
    SETB TR1

    ; Initialize the DAC0808
    SETB CS
    SETB WR
    CLR ADR
    MOV P0, #00h
    CLR CS
    NOP
    SETB WR
    SETB CS

    ; Set the initial voltage level
    MOV A, LEVEL
    CALL SET_VOLTAGE

    ; Main loop
    LOOP:
        ; Check for key presses
        CLR K1
        JNB K1, $+3
        CALL CHANGE_VOLTAGE
        SETB K1

        CLR K2
        JNB K2, $+3
        CALL CHANGE_VOLTAGE
        SETB K2

        ; Delay
        MOV R7, #DELAY
        DELAY_LOOP:
            DJNZ R7, DELAY_LOOP

        JMP LOOP

; Interrupt service routine
TIMER0_ISR:
    ; Toggle the voltage output pins
    CPL VOUT1
    CPL VOUT2

    ; Reset the timer
    MOV TH0, #0FEh
    MOV TL0, #0CCh

    RETI

; Subroutine to set the voltage level
SET_VOLTAGE:
    ; Convert the voltage level to a binary value
    CJNE A, #V1, NOT_V1
    MOV A, #00000000b
    JMP SET_DAC
    NOT_V1:
    CJNE A, #V2, NOT_V2
    MOV A, #00011000b
    JMP SET_DAC
    NOT_V2:
    CJNE A, #V3, NOT_V3
    MOV A, #00110000b
    JMP SET_DAC
    NOT_V3:
    CJNE A, #V4, NOT_V4
    MOV A, #01001000b
    JMP SET_DAC
    NOT_V4:
    MOV A, #01111000b

    ; Set the DAC0808 output
    SET_DAC:
    CLR CS
    MOV P0, A
    CLR WR
    NOP
    SETB WR
    SETB CS

    RET

; Subroutine to change the voltage level
CHANGE_VOLTAGE:
    ; Increment the voltage level
    INC LEVEL
    CJNE LEVEL, #V5+1, NOT_MAX
    MOV LEVEL, #V1
    NOT_MAX:

    ; Set the new voltage level
    MOV A, LEVEL
    CALL SET_VOLTAGE

    RET

END