利用F28335定时DA输出仿真与设计，设计三个小任务，写出流程完整代码

任务一：生成一个正弦波

#include "DSP2833x_Device.h"
#include "DSP2833x_Examples.h"

#define PI 3.14159265358979323846

Uint16 sine_table[256];

void Init_Sine_Table(void)
{
    int i;
    for(i = 0; i < 256; i++)
    {
        sine_table[i] = (Uint16)(2047*sin(2*PI*i/256) + 2047);
    }
}

void main(void)
{
    InitSysCtrl();
    InitPieCtrl();
    InitPieVectTable();
    Init_Sine_Table();

    EALLOW;
    GpioCtrlRegs.GPAMUX1.bit.GPIO0 = 1; //PWM1A
    GpioCtrlRegs.GPAMUX1.bit.GPIO1 = 1; //PWM1B
    EDIS;

    EPwm1Regs.TBPRD = 7500; //设置PWM周期为10kHz
    EPwm1Regs.TBCTL.bit.CTRMODE = TB_COUNT_UPDOWN;
    EPwm1Regs.TBCTL.bit.PHSEN = TB_DISABLE;
    EPwm1Regs.TBCTL.bit.SYNCOSEL = TB_CTR_ZERO;
    EPwm1Regs.AQCTLA.bit.ZRO = AQ_SET;
    EPwm1Regs.AQCTLA.bit.CAU = AQ_CLEAR;
    EPwm1Regs.AQCTLB.bit.ZRO = AQ_SET;
    EPwm1Regs.AQCTLB.bit.CBU = AQ_CLEAR;

    EPwm1Regs.CMPA.bit.CMPA = sine_table[0];

    EPwm1Regs.ETSEL.bit.SOCAEN = 1;
    EPwm1Regs.ETSEL.bit.SOCASEL = ET_CTR_ZERO;
    EPwm1Regs.ETPS.bit.SOCAPRD = ET_1ST;

    EPwm1Regs.TBCTL.bit.HSPCLKDIV = 0;
    EPwm1Regs.TBCTL.bit.CLKDIV = 0;
    EPwm1Regs.TBCTL.bit.PRDLD = TB_SHADOW;
    EPwm1Regs.TBCTL.bit.PHSEN = TB_DISABLE;

    EPwm1Regs.TBCTL.bit.CTRMODE = TB_COUNT_UPDOWN;
    EPwm1Regs.TBCTL.bit.PHSEN = TB_DISABLE;
    EPwm1Regs.TBCTL.bit.SYNCOSEL = TB_CTR_ZERO;

    EPwm1Regs.CMPCTL.bit.SHDWAMODE = CC_SHADOW;
    EPwm1Regs.CMPCTL.bit.LOADAMODE = CC_CTR_ZERO;

    EPwm1Regs.CMPA.bit.CMPA = sine_table[0];
    EPwm1Regs.CMPB.bit.CMPB = sine_table[0];

    EPwm1Regs.ETSEL.bit.SOCAEN = 1;
    EPwm1Regs.ETSEL.bit.SOCASEL = ET_CTR_ZERO;
    EPwm1Regs.ETPS.bit.SOCAPRD = ET_1ST;

    EPwm1Regs.TBCTL.bit.CTRMODE = TB_COUNT_UPDOWN;
    EPwm1Regs.TBCTL.bit.PHSEN = TB_DISABLE;
    EPwm1Regs.TBCTL.bit.SYNCOSEL = TB_CTR_ZERO;

    EPwm1Regs.TBCTL.bit.HSPCLKDIV = 0;
    EPwm1Regs.TBCTL.bit.CLKDIV = 0;
    EPwm1Regs.TBCTL.bit.PRDLD = TB_SHADOW;
    EPwm1Regs.TBCTL.bit.PHSEN = TB_DISABLE;

    EPwm1Regs.TBCTL.bit.CTRMODE = TB_COUNT_UPDOWN;
    EPwm1Regs.TBCTL.bit.PHSEN = TB_DISABLE;
    EPwm1Regs.TBCTL.bit.SYNCOSEL = TB_CTR_ZERO;

    EPwm1Regs.CMPCTL.bit.SHDWAMODE = CC_SHADOW;
    EPwm1Regs.CMPCTL.bit.LOADAMODE = CC_CTR_ZERO;

    EPwm1Regs.CMPA.bit.CMPA = sine_table[0];
    EPwm1Regs.CMPB.bit.CMPB = sine_table[0];

    EPwm1Regs.ETSEL.bit.SOCAEN = 1;
    EPwm1Regs.ETSEL.bit.SOCASEL = ET_CTR_ZERO;
    EPwm1Regs.ETPS.bit.SOCAPRD = ET_1ST;

    EALLOW;
    SysCtrlRegs.PCLKCR0.bit.TBCLKSYNC = 1;
    EDIS;

    EPwm1Regs.TBCTL.bit.CTRMODE = TB_COUNT_UPDOWN;
    EPwm1Regs.TBCTL.bit.PHSEN = TB_DISABLE;
    EPwm1Regs.TBCTL.bit.SYNCOSEL = TB_CTR_ZERO;

    while(1)
    {

    }
}

任务二：实现PWM波形调制

#include "DSP2833x_Device.h"
#include "DSP2833x_Examples.h"

void main(void)
{
    InitSysCtrl();
    InitPieCtrl();
    InitPieVectTable();

    EALLOW;
    GpioCtrlRegs.GPAMUX1.bit.GPIO0 = 1;
    GpioCtrlRegs.GPAMUX1.bit.GPIO1 = 1;
    GpioCtrlRegs.GPAMUX1.bit.GPIO2 = 1;
    GpioCtrlRegs.GPAMUX1.bit.GPIO3 = 1;
    EDIS;

    EPwm1Regs.TBPRD = 4500;
    EPwm1Regs.TBCTL.bit.CTRMODE = TB_COUNT_UPDOWN;
    EPwm1Regs.TBCTL.bit.PHSEN = TB_DISABLE;
    EPwm1Regs.TBCTL.bit.SYNCOSEL = TB_CTR_ZERO;

    EPwm1Regs.CMPA.bit.CMPA = 2250; //占空比50%

    EPwm1Regs.AQCTLA.bit.CAU = AQ_SET; //高电平
    EPwm1Regs.AQCTLA.bit.CAD = AQ_CLEAR; //低电平
    EPwm1Regs.AQCTLB.bit.CBU = AQ_SET;
    EPwm1Regs.AQCTLB.bit.CBD = AQ_CLEAR;

    EALLOW;
    SysCtrlRegs.PCLKCR0.bit.TBCLKSYNC = 1;
    EDIS;

    while(1)
    {

    }
}

任务三：实现ADC采样和输出

#include "DSP2833x_Device.h"
#include "DSP2833x_Examples.h"

#define ADC_SOC_NUMBER 0 //使用的ADC SOC号码

Uint16 AdcData[2]; //存放ADC采样结果的数组

void ADC_Init(void)
{
    EALLOW;
    AdcRegs.ADCCTL1.bit.ADCREFSEL = 0; //内部参考电压
    AdcRegs.ADCCTL1.bit.ADCBGPWD = 1; //开启内部参考电压缓冲区
    AdcRegs.ADCCTL1.bit.ADCREFPWD = 1; //开启内部参考电压缓冲区
    AdcRegs.ADCCTL1.bit.ADCPWDN = 1; //开启ADC电源
    AdcRegs.ADCCTL2.bit.CLKDIV2EN = 0; //不分频
    AdcRegs.ADCCTL2.bit.ADCNONOVERLAP = 1; //非重叠采样
    AdcRegs.ADCCTL2.bit.CHARGEPUMPEN = 1; //开启充电泵
    AdcRegs.ADCCTL2.bit.INTPULSEPOS = 1; //中断脉冲在采样之后

    AdcRegs.ADCSOC0CTL.bit.CHSEL = 0; //采样通道
    AdcRegs.ADCSOC0CTL.bit.ACQPS = 6; //采样保持时间
    AdcRegs.ADCSOC0CTL.bit.TRIGSEL = 5; //触发源EPWM1SOCA
    AdcRegs.ADCSOC0CTL.bit.HI_PRIORITY = 1; //高优先级

    AdcRegs.INTSEL1N2.bit.INT1SEL = ADC_SOC_NUMBER; //中断1与ADC SOC关联
    AdcRegs.INTSEL1N2.bit.INT1E = 1; //开启ADC中断1
    AdcRegs.INTSEL1N2.bit.INT1CONT = 1; //循环模式
    AdcRegs.INTSEL1N2.bit.INT1SEL2 = 0; //中断1触发源为EOC0
    AdcRegs.INTSEL1N2.bit.INT1SEL1 = 0; //中断1触发源为EOC0
    PieCtrlRegs.PIEIER1.bit.INTx6 = 1; //开启ADC中断1
    IER |= M_INT1;

    AdcRegs.ADCSOCFRC1.all = 0x0001; //启动ADC SOC0采样
    EDIS;
}

interrupt void Adc_ISR(void)
{
    AdcData[0] = AdcResult.ADCRESULT0; //存放采样结果
    AdcRegs.ADCINTFLGCLR.bit.ADCINT1 = 1; //清除ADC中断1标志位
    PieCtrlRegs.PIEACK.all = PIEACK_GROUP1; //清除PIE中断标志位
}

void main(void)
{
    InitSysCtrl();
    InitPieCtrl();
    InitPieVectTable();
    ADC_Init();

    EALLOW;
    GpioCtrlRegs.GPAMUX1.bit.GPIO0 = 1;
    GpioCtrlRegs.GPAMUX1.bit.GPIO1 = 1;
    GpioCtrlRegs.GPAMUX1.bit.GPIO2 = 1;
    GpioCtrlRegs.GPAMUX1.bit.GPIO3 = 1;
    EDIS;

    EPwm1Regs.TBPRD = 4500;
    EPwm1Regs.TBCTL.bit.CTRMODE = TB_COUNT_UPDOWN;
    EPwm1Regs.TBCTL.bit.PHSEN = TB_DISABLE;
    EPwm1Regs.TBCTL.bit.SYNCOSEL = TB_CTR_ZERO;

    EPwm1Regs.CMPA.bit.CMPA = 2250; //占空比50%

    EPwm1Regs.AQCTLA.bit.CAU = AQ_SET; //高电平
    EPwm1Regs.AQCTLA.bit.CAD = AQ_CLEAR; //低电平
    EPwm1Regs.AQCTLB.bit.CBU = AQ_SET;
    EPwm1Regs.AQCTLB.bit.CBD = AQ_CLEAR;

    EALLOW;
    SysCtrlRegs.PCLKCR0.bit.TBCLKSYNC = 1;
    EDIS;

    while(1)
    {
        EPwm1Regs.CMPA.bit.CMPA = AdcData[0]; //将ADC采样结果输出到PWM的占空比上
    }
}