TMS320F28335: 28338PWM配置问题

ke Lan

Prodigy 140 points

Part Number: TMS320F28335

请问这个问题有什么解释吗？

1 年多前

0 Yale Li 李耀先 1 年多前

TI__Guru 65745 points

不好意思之前漏掉了。

有两点我需要再确认一下：

1. 初始化ePWM模块的流程是怎样的？也就是说在初始化之前有没有关闭ePWM模块的外设时钟，然后在配置完成后再打开？

2. 试一下在配置的最后再手动清一下TBCTR。

0 ke Lan 1 年多前回复 Yale Li 李耀先

Prodigy 140 points

void Init_EPWM()
{
    EALLOW;
    SysCtrlRegs.PCLKCR0.bit.TBCLKSYNC = 0; // Disable TBCLK within the EPWM
    EDIS;
    
    Init_epwm1();
    Init_epwm2();
    // Init_epwm3();
    
    EALLOW;
    SysCtrlRegs.PCLKCR0.bit.TBCLKSYNC = 1; // Enable TBCLK within the EPWM
    EDIS;
}

//=======================================================
//函数名称: Init_epwm1()
//功能: 初始化EPWM1为带死区互补输出(AHC)的可变频率的PWM 逆变级
//输入:
//返回:
//备注:
//=======================================================
void Init_epwm1(void)
{

    EPwm1Regs.TBCTL.bit.CTRMODE = TB_COUNT_UPDOWN; // Count up-down
    EPwm1Regs.TBCTL.bit.HSPCLKDIV = TB_DIV1; // TBCLK = EPWMCLK /（HSPCLKDIV× CLKDIV）
    EPwm1Regs.TBCTL.bit.CLKDIV = TB_DIV1; // TBCLK = 150M/（1*1）= 150MHz
    EPwm1Regs.TBCTL.bit.PHSEN = TB_DISABLE; // Enable phase loading
    EPwm1Regs.TBCTL.bit.PRDLD = TB_SHADOW; // TBPRD is loaded from its shadow register
    
    EPwm1Regs.TBPRD = EPWM_PRD; // Set timer period (100kHz)
    EPwm1Regs.TBPHS.half.TBPHS = 0x0000; // Phase is 0
    EPwm1Regs.TBCTR = 0x0000; // Clear counter
    EPwm1Regs.TBCTL.bit.SYNCOSEL = TB_CTR_ZERO; // 同步信号输出选择TBCTR=0
    EPwm1Regs.CMPCTL.bit.SHDWAMODE = CC_SHADOW; // CMPA Shadow mode
    EPwm1Regs.CMPCTL.bit.LOADAMODE = CC_CTR_ZERO; // Load on CTR = 0
    EPwm1Regs.CMPCTL.bit.SHDWBMODE = CC_SHADOW; // CMPA Shadow mode
    EPwm1Regs.CMPCTL.bit.LOADBMODE = CC_CTR_ZERO; // Load on CTR = 0
    
    EPwm1Regs.CMPA.half.CMPA = 2*D* EPWM_PRD; // Initial duty
    
    EPwm1Regs.AQCTLA.bit.CAU = AQ_CLEAR; // TBCTR = CMPA on Down Count：Clear
    EPwm1Regs.AQCTLA.bit.CAD = AQ_NO_ACTION; // TBCTR = CMPA on Up Count：NO ACTION
    EPwm1Regs.AQCTLA.bit.ZRO = AQ_SET; // TBCTR = 0 on Up Count：Set
    
    // EPwm1Regs.AQCTLB.bit.CAU = AQ_CLEAR; // TBCTR = CMPA on Down Count：Clear
    // EPwm1Regs.AQCTLB.bit.CAD = AQ_NO_ACTION; // TBCTR = CMPA on Up Count：NO ACTION
    // EPwm1Regs.AQCTLB.bit.ZRO = AQ_SET; // T BCTR = 0 on Up Count：Set
    
    EPwm1Regs.AQCTLB.bit.CAU = AQ_NO_ACTION;
    EPwm1Regs.AQCTLB.bit.CAD = AQ_CLEAR;
    EPwm1Regs.AQCTLB.bit.ZRO = AQ_SET;
    //DELAY_US(100000);
    EPwm1Regs.DBCTL.bit.OUT_MODE = DB_FULL_ENABLE; //0x3 MODE2 AHC high level delay (AHC)死区双边使能
    EPwm1Regs.DBCTL.bit.POLSEL = DB_ACTV_HIC; //0x2 A不反转，B反转
    EPwm1Regs.DBCTL.bit.IN_MODE = DBA_RED_DBB_FED;
    
    EPwm1Regs.DBRED = EPWM1_DBRED; // 上升沿延时 注意：只有10位，最大1023
    EPwm1Regs.DBFED = EPWM1_DBFED; // 下降沿延时 注意：只有10位，最大1023
    
    EALLOW;
    EPwm1Regs.TZSEL.bit.OSHT1 = 1; //单次触发联防
    // EPwm1Regs.TZSEL.bit.OSHT2 = 1; //单次触发联防
    
    EPwm1Regs.TZCTL.bit.TZA = TZ_FORCE_LO; //强制A低电平
    EPwm1Regs.TZCTL.bit.TZB = TZ_FORCE_LO; //强制B低电平
    //
    // // Enable TZ interrupt
    //
    EPwm1Regs.TZEINT.bit.OST = 1;
    EDIS;
    //
    EALLOW;
    EPwm1Regs.ETSEL.bit.INTSEL = ET_CTR_ZERO; //过零点触发中断
    EPwm1Regs.ETSEL.bit.INTEN = 1; //使能中断
    EPwm1Regs.ETPS.bit.INTPRD = ET_1ST; //每次过零产生中断
    EDIS;
    
    
    //计数器计数等于0时触发ADC转换
    // EPwm1Regs.ETSEL.bit.SOCASEL = ET_CTR_ZERO; // Counter = 0
    // EPwm1Regs.ETPS.bit.SOCAPRD = ET_1ST; // Generate SOCA pulse on 1st event
    // EPwm1Regs.ETCLR.bit.SOCA = 1; // Clear SOCA flag
    // EPwm1Regs.ETSEL.bit.SOCAEN = 1; // Enable SOCA
    
    // EPwm1Regs.ETCLR.bit.INT = 1; // Clear INT flag
    // EPwm1Regs.ETSEL.bit.INTEN = 0; // Disable INT
}



void Init_epwm2(void)
{


    EPwm2Regs.TBCTL.bit.CTRMODE = TB_COUNT_UPDOWN; // Count up-down
    EPwm2Regs.TBCTL.bit.HSPCLKDIV = TB_DIV1; // TBCLK = EPWMCLK /（HSPCLKDIV× CLKDIV）
    EPwm2Regs.TBCTL.bit.CLKDIV = TB_DIV1; // TBCLK = 150M/（1*1）= 150MHz
    EPwm2Regs.TBCTL.bit.PHSEN = TB_ENABLE; // Enable phase loading
    EPwm2Regs.TBCTL.bit.PRDLD = TB_SHADOW; // TBPRD is loaded from its shadow register
    
    EPwm2Regs.TBPRD = EPWM_PRD; // Set timer period (4.8kHz)
    
    EPwm2Regs.TBPHS.half.TBPHS = 0;
    EPwm2Regs.TBCTR = 0x0000; // Clear counter
    EPwm2Regs.TBCTL.bit.SYNCOSEL = TB_SYNC_IN; // 同步信号输出选择外部同步信号输入EPWMxSYNCO
    
    EPwm2Regs.CMPCTL.bit.SHDWAMODE = CC_SHADOW; // CMPA Shadow mode
    EPwm2Regs.CMPCTL.bit.LOADAMODE = CC_CTR_ZERO; // Load on CTR = 0
    EPwm2Regs.CMPCTL.bit.SHDWBMODE = CC_SHADOW; // CMPA Shadow mode
    EPwm2Regs.CMPCTL.bit.LOADBMODE = CC_CTR_ZERO; // Load on CTR = 0
    
    
    EPwm2Regs.CMPA.half.CMPA = 2*D* EPWM_PRD; // Initial duty
    
    // EPwm2Regs.AQCTLA.bit.CAU = AQ_CLEAR; // TBCTR = CMPA on Down Count：Clear
    // EPwm2Regs.AQCTLA.bit.CAD = AQ_NO_ACTION; // TBCTR = CMPA on Up Count：NO ACTION
    // EPwm2Regs.AQCTLA.bit.ZRO = AQ_SET; // TBCTR = 0 on Up Count：Set
    //
    // EPwm2Regs.AQCTLB.bit.CAU = AQ_NO_ACTION;
    // EPwm2Regs.AQCTLB.bit.CAD = AQ_CLEAR;
    // EPwm2Regs.AQCTLB.bit.ZRO = AQ_SET;
    //
    // EPwm2Regs.DBCTL.bit.OUT_MODE = DB_FULL_ENABLE; //0x3 MODE2 AHC high level delay (AHC)死区双边使能
    // EPwm2Regs.DBCTL.bit.POLSEL = DB_ACTV_HIC; //0x1 A不反转，B反转
    // EPwm2Regs.DBCTL.bit.IN_MODE = DBA_RED_DBB_FED;
    
    // EPwm2Regs.AQCTLA.bit.CAU = AQ_NO_ACTION; // TBCTR = CMPA on Down Count：Clear
    // EPwm2Regs.AQCTLA.bit.CAD = AQ_SET; // TBCTR = CMPA on Up Count：Set
    // EPwm2Regs.AQCTLA.bit.ZRO = AQ_CLEAR;
    //
    // EPwm2Regs.AQCTLB.bit.CAU = AQ_SET;
    // EPwm2Regs.AQCTLB.bit.CAD = AQ_NO_ACTION;
    // EPwm2Regs.AQCTLB.bit.ZRO = AQ_CLEAR;
    EPwm2Regs.AQCTLA.bit.CAU = AQ_CLEAR; // TBCTR = CMPA on Down Count：Clear
    EPwm2Regs.AQCTLA.bit.CAD = AQ_NO_ACTION; // TBCTR = CMPA on Up Count：NO ACTION
    EPwm2Regs.AQCTLA.bit.ZRO = AQ_SET; // TBCTR = 0 on Up Count：Set
    
    // EPwm2Regs.AQCTLA.bit.CAU = AQ_CLEAR; // TBCTR = CMPA on Down Count：Clear
    // EPwm2Regs.AQCTLA.bit.CAD = AQ_NO_ACTION; // TBCTR = CMPA on Up Count：NO ACTION
    // EPwm2Regs.AQCTLA.bit.ZRO = AQ_NO_ACTION; // TBCTR = 0 on Up Count：Set
    //
    // EPwm2Regs.AQCTLB.bit.CAU = AQ_CLEAR;
    // EPwm2Regs.AQCTLB.bit.CAD = AQ_NO_ACTION;
    // EPwm2Regs.AQCTLB.bit.ZRO = AQ_NO_ACTION;
    
    EPwm2Regs.AQCTLB.bit.CAU = AQ_NO_ACTION;
    EPwm2Regs.AQCTLB.bit.CAD = AQ_CLEAR;
    EPwm2Regs.AQCTLB.bit.ZRO = AQ_SET;
    
    EPwm2Regs.DBCTL.bit.OUT_MODE = DB_FULL_ENABLE; //0x3 MODE2 AHC high level delay (AHC)死区双边使能
    EPwm2Regs.DBCTL.bit.POLSEL = DB_ACTV_HIC; //0x2 A不反转，B反转
    // EPwm2Regs.DBCTL.bit.POLSEL = DB_ACTV_HI; //0x2 A不反转，B不反转
    EPwm2Regs.DBCTL.bit.IN_MODE = DBA_RED_DBB_FED;
    
    // EPwm2Regs.DBCTL.bit.OUT_MODE = DB_FULL_ENABLE; //0x3 MODE2 AHC high level delay (AHC)死区双边使能
    // EPwm2Regs.DBCTL.bit.POLSEL = DB_ACTV_HIC; //0x2
    // EPwm2Regs.DBCTL.bit.IN_MODE = DBA_RED_DBB_FED;
    
    EPwm2Regs.DBRED = EPWM2_DBRED; // 上升沿延时 上升死区为0.5%的占空比 0.5%个TBPRD(150MHz) 注意：只有10位，最大1023
    EPwm2Regs.DBFED = EPWM2_DBFED; // 下降沿延时 下降死区为0.5%的占空比 0.5%个TBPRD(150MHz) 注意：只有10位，最大1023
    
    
    
    EALLOW;
    
    EPwm2Regs.TZSEL.bit.OSHT1 = 1;
    EPwm2Regs.TZCTL.bit.TZA = TZ_FORCE_LO;
    EPwm2Regs.TZCTL.bit.TZB = TZ_FORCE_LO;
    
    
    //Enable TZ interrupt
    
    // EPwm2Regs.TZEINT.bit.CBC =1;
    EPwm2Regs.TZEINT.bit.OST = 1;
    EDIS;
    
    // EALLOW;
    // //EPwm1Regs.AQCSFRC.all=0x05; //强制低
    // EPwm2Regs.AQCSFRC.all=0x05; //强制低
    // // EPwm3Regs.AQCSFRC.all=0x05;
    // // EPwm6Regs.AQCSFRC.all=0x05;
    // EPwm2Regs.DBCTL.bit.POLSEL = 0x0; //不反转极性
    // EDIS;
}

如图上代码所示，Init_EPWM()为PWM初始化函数，其流程是先关闭TBCLKSYNC时基时钟，再进行配置，配置结束后再开启时基时钟。另外你说的外设时钟，不知道是不是这片代码。这片代码在工程文件的DSP2833x_SysCtrl.c源文件里，并未改动。

SysCtrlRegs.PCLKCR0.bit.TBCLKSYNC = 0; // Disable TBCLK within the ePWM
SysCtrlRegs.PCLKCR1.bit.EPWM1ENCLK = 1; // ePWM1
SysCtrlRegs.PCLKCR1.bit.EPWM2ENCLK = 1; // ePWM2
SysCtrlRegs.PCLKCR1.bit.EPWM3ENCLK = 1; // ePWM3
SysCtrlRegs.PCLKCR1.bit.EPWM4ENCLK = 1; // ePWM4
SysCtrlRegs.PCLKCR1.bit.EPWM5ENCLK = 1; // ePWM5
SysCtrlRegs.PCLKCR1.bit.EPWM6ENCLK = 1; // ePWM6
SysCtrlRegs.PCLKCR0.bit.TBCLKSYNC = 1; // Enable TBCLK within the ePWM

2.配置完后清除了TBCLR计数器，还是有这个现象。

3，这个现象出现在在翻转的那一路PWM上，不论PWM动作模块怎么配置，只要在死区模块中把该路PWM翻转，PWM输出不论输出高电平，还是低电平，第一个脉冲时钟就有一段高电平。这段高电平过后就是正常的PWM波。这个现象也出现在直接购买的28335开发板上。

0 Yale Li 李耀先 1 年多前回复 ke Lan

TI__Guru 65745 points

我实验一下

0 Yale Li 李耀先 1 年多前回复 Yale Li 李耀先

TI__Guru 65745 points

我复现到了你描述的现象

0 Yale Li 李耀先 1 年多前回复 Yale Li 李耀先

TI__Guru 65745 points

为了方便之后查看，我把DB的配置发上来：

另外为了方便查看，我把你之前上传的代码的格式改了一下

0 ke Lan 1 年多前回复 Yale Li 李耀先

Prodigy 140 points

对，是这种配置，这个现象会导致我们电路会发生保护。而且EPWM1B这段高电平持续时间高一些，EPWM2B高电平持续时间低一些。

0 Yale Li 李耀先 1 年多前回复 ke Lan

TI__Guru 65745 points

关键配置：

EPwm1Regs.TBCTL.bit.CTRMODE = TB_COUNT_UPDOWN;

EPwm1Regs.TBCTR = 0x0000;

EPwm1Regs.CMPA.half.CMPA = 2 * D * EPWM_PRD;

EPwm1Regs.AQCTLA.bit.CAU = AQ_CLEAR;
EPwm1Regs.AQCTLA.bit.ZRO = AQ_SET;

EPwm1Regs.AQCTLB.bit.CAD = AQ_CLEAR;
EPwm1Regs.AQCTLB.bit.ZRO = AQ_SET;

EPwm1Regs.DBCTL.bit.OUT_MODE = DB_FULL_ENABLE;
EPwm1Regs.DBCTL.bit.POLSEL = DB_ACTV_HIC;       //B reverse
EPwm1Regs.DBCTL.bit.IN_MODE = DBA_RED_DBB_FED;

EPwm1Regs.DBRED = EPWM1_DBRED;
EPwm1Regs.DBFED = EPWM1_DBFED;

实验结果：