TMS320F28035: PWM怎样才能初始低电平

chen zheng 说：

我的28035在还没发波前epwm2a和epwm3a输出的是高电平

还没发波前就是高电平，那么可能是IO的配置问题。

你好，我的IO口配置如下：

//
// InitEPwm2Gpio - This function initializes GPIO pins to function as EPwm2
//
void 
InitEPwm2Gpio(void)
{
    EALLOW;

    //
    // Disable internal pull-up for the selected output pins
    // for reduced power consumption
    // Pull-ups can be enabled or disabled by the user.
    // This will enable the pullups for the specified pins.
    // Comment out other unwanted lines.
    //
    GpioCtrlRegs.GPAPUD.bit.GPIO2 = 1;    // Disable pull-up on GPIO2 (EPWM2A)
    GpioCtrlRegs.GPAPUD.bit.GPIO3 = 1;    // Disable pull-up on GPIO3 (EPWM2B)

    //
    // Configure EPwm-2 pins using GPIO regs
    // This specifies which of the possible GPIO pins will be
    // EPWM2 functional pins.
    // Comment out other unwanted lines.
    //
    GpioCtrlRegs.GPAMUX1.bit.GPIO2 = 1;   // Configure GPIO2 as EPWM2A
    GpioCtrlRegs.GPAMUX1.bit.GPIO3 = 1;   // Configure GPIO3 as EPWM2B

    EDIS;
}

//
// InitEPwm3Gpio - This function initializes GPIO pins to function as EPwm3
//
void 
InitEPwm3Gpio(void)
{
    EALLOW;

    // Disable internal pull-up for the selected output pins
    // for reduced power consumption 
    // Pull-ups can be enabled or disabled by the user.
    // This will enable the pullups for the specified pins.
    // Comment out other unwanted lines.
    //
    GpioCtrlRegs.GPAPUD.bit.GPIO4 = 1;    // Disable pull-up on GPIO4 (EPWM3A)
    GpioCtrlRegs.GPAPUD.bit.GPIO5 = 1;    // Disable pull-up on GPIO5 (EPWM3B)

    //
    // Configure EPwm-3 pins using GPIO regs
    // This specifies which of the possible GPIO pins will be
    // EPWM3 functional pins.
    // Comment out other unwanted lines.
    //
    GpioCtrlRegs.GPAMUX1.bit.GPIO4 = 1;   // Configure GPIO4 as EPWM3A
    GpioCtrlRegs.GPAMUX1.bit.GPIO5 = 1;   // Configure GPIO5 as EPWM3B

    EDIS;
}

就是把GUAPUD和GPAMUX都设置为1，是否需要修改？谢谢

你好，GPIO应该没问题。你这里设置了couznter 等于0的时候置位，尝试将其改成清零。

EPwm2Regs.AQCTLA.bit.ZRO = AQ_SET;

你好，我的代码里 设置的是：

EPwm2Regs.AQCTLA.bit.ZRO = AQ_SET; 
EPwm2Regs.AQCTLA.bit.CAU = AQ_CLEAR;

这与你回答的

EPwm2Regs.AQCTLA.bit.ZRO = AQ_SET;

是一样的呀，是要把我代码里的

EPwm2Regs.AQCTLA.bit.CAU = AQ_CLEAR;

这一行删掉吗，谢谢。

不是的，把

EPwm2Regs.AQCTLA.bit.ZRO = AQ_SET

改成

EPwm2Regs.AQCTLA.bit.ZRO = AQ_CLEAR

好的，那还需要把

EPwm2Regs.AQCTLA.bit.CAU = AQ_CLEAR;

改成

EPwm2Regs.AQCTLA.bit.CAU = AQ_SET;

吗？因为CAU和ZRO好像是一起设置的

对的，这里是要一起设置的。

PWM对应IO初始化时禁用上拉

PWM初始化前，先手动OST

这样就可以了

在开机时复位OST。

我之前设置过，设置之后占空比的大小变了

具体怎么操作呢，谢谢

你好，您给的这两行代码应该放在epwm配置代码里的哪个位置呢，谢谢

上面代码在EPWM初始化前。

void InitEPwm2(void)
{
    EPwm2Regs.TZFRC.bit.OST = 1;
    EPwm2Regs.TZCLR.all = 0*3F;

    EPwm2Regs.TBPRD = TB_PERIOD;
    EPwm2Regs.CMPA.half.CMPA = DUTY_VALUE;
    EPwm2Regs.TBPHS.half.TBPHS = 0;          // Set Phase register to zero
    EPwm2Regs.TBCTL.bit.HSPCLKDIV = TB_DIV1; // Clock ratio to SYSCLKOUT
    EPwm2Regs.TBCTL.bit.CLKDIV = TB_DIV1;
    EPwm2Regs.TBCTL.bit.CTRMODE = TB_COUNT_UP; // Asymmetrical mode
    EPwm2Regs.TBCTL.bit.PHSEN = TB_DISABLE;    // Master module
    EPwm2Regs.TBCTL.bit.PRDLD = TB_SHADOW;
    EPwm2Regs.TBCTL.bit.SYNCOSEL = TB_CTR_ZERO;

    EPwm2Regs.CMPCTL.bit.SHDWAMODE = CC_SHADOW;
    EPwm2Regs.CMPCTL.bit.SHDWBMODE = CC_SHADOW;
    EPwm2Regs.CMPCTL.bit.LOADAMODE = CC_CTR_ZERO; // load on CTR=Zero
    EPwm2Regs.CMPCTL.bit.LOADBMODE = CC_CTR_ZERO; // load on CTR=Zero

//    EPwm2Regs.AQCTLA.bit.ZRO = AQ_SET; // set actions for EPwm2A
//    EPwm2Regs.AQCTLA.bit.CAU = AQ_CLEAR;
    EPwm2Regs.AQCTLA.bit.ZRO = AQ_CLEAR;
    EPwm2Regs.AQCTLA.bit.CAU = AQ_SET;

//    EPwm2Regs.AQCSFRC.bit.CSFA = 0;

    // Interrupt where we will change the Compare Values
    EPwm2Regs.ETSEL.bit.INTSEL = ET_CTR_ZERO; // Select INT on Zero event
    EPwm2Regs.ETSEL.bit.INTEN = 1;            // Enable INT
    EPwm2Regs.ETPS.bit.INTPRD = ET_1ST;       // Generate INT on 3rd event

    EPwm2Regs.DBCTL.bit.OUT_MODE = DB_FULL_ENABLE; // enable Dead-band module

    EPwm2Regs.DBFED = DB_VALUE; // FED = 300 TBCLKs initially
    EPwm2Regs.DBRED = DB_VALUE; // RED = 300 TBCLKs initially

}

void InitEPwm3(void)
{
    EPwm3Regs.TZFRC.bit.OST = 1;
    EPwm3Regs.TZCLR.all = 0*3F;

    EPwm3Regs.TBPRD = TB_PERIOD; // Period = 15000 TBCLK counts
    EPwm3Regs.CMPA.half.CMPA = DUTY_VALUE;
    EPwm3Regs.TBPHS.half.TBPHS = 0;          // Set Phase register to zero initially
    EPwm3Regs.TBCTL.bit.HSPCLKDIV = TB_DIV1; // Clock ratio to SYSCLKOUT
    EPwm3Regs.TBCTL.bit.CLKDIV = TB_DIV1;
    EPwm3Regs.TBCTL.bit.CTRMODE = TB_COUNT_UP; // Asymmetrical mode
    EPwm3Regs.TBCTL.bit.PHSEN = TB_ENABLE;     // Slave module
    EPwm3Regs.TBCTL.bit.PRDLD = TB_SHADOW;
    EPwm3Regs.TBCTL.bit.SYNCOSEL = TB_SYNC_IN; // sync flow-through

    EPwm3Regs.CMPCTL.bit.SHDWAMODE = CC_SHADOW;
    EPwm3Regs.CMPCTL.bit.SHDWBMODE = CC_SHADOW;
    EPwm3Regs.CMPCTL.bit.LOADAMODE = CC_CTR_ZERO; // load on CTR=Zero
    EPwm3Regs.CMPCTL.bit.LOADBMODE = CC_CTR_ZERO; // load on CTR=Zero

//    EPwm3Regs.AQCTLA.bit.ZRO = AQ_SET; // set actions for EPwm3A
//    EPwm3Regs.AQCTLA.bit.CAU = AQ_CLEAR;
    EPwm3Regs.AQCTLA.bit.ZRO = AQ_CLEAR;
    EPwm3Regs.AQCTLA.bit.CAU = AQ_SET;

//    EPwm3Regs.AQCSFRC.bit.CSFA = 0;

    // Interrupt where we will change the Compare Values
    EPwm3Regs.ETSEL.bit.INTSEL = ET_CTR_ZERO; // Select INT on Zero event
    EPwm3Regs.ETSEL.bit.INTEN = 1;            // Enable INT
    EPwm3Regs.ETPS.bit.INTPRD = ET_1ST;       // Generate INT on 3rd event

    EPwm3Regs.DBCTL.bit.OUT_MODE = DB_FULL_ENABLE; // enable Dead-band module

    EPwm3Regs.DBFED = DB_VALUE; // FED = 30 TBCLKs initially
    EPwm3Regs.DBRED = DB_VALUE; // RED = 40 TBCLKs initially
    // Run Time (Note: Example execution of one run-time instant)
    //============================================================
    EPwm3Regs.TBPHS.half.TBPHS = TB_PERIOD / 2;
    //    EPwm3Regs.TBPHS.half.TBPHS = 15000 - yixiangjiao; // Set Phase reg to 300/1200 * 360 = 90 deg
    //    EPwm3Regs.DBFED = FED2_NewValue; // Update ZVS transition interval
    //    EPwm3Regs.DBRED = RED2_NewValue; // Update ZVS transition interval

}

你好，是像这样，在epwm2和epwm3配置的第一航添加您说的代码进去吗，谢谢