[参考译文] TMS320F28374D：PWM 全局加载问题

尊敬的 Angela：

感谢您提出详细的问题。 是否知道 GLDCTL2寄存器中的 OSHTLD 位是否正在更新以导致更新？

如果使用 driverlib、则会转换为以下函数： ePWM_setGlobalLoadOneShotLatch()

同样、为了使用与上面项目4和6分开的全局加载功能、需要将 GLDCTL 的 GLD 位设置为1。

这将转换 为 driverlib 中的 ePWM_enableGlobalLoad()。

此外、您能否描述更新的位置？ 计时器 ISR、ADC ISR？

此致、

Marlyn

您好、Marlyn、

GLD 位已设置为1。 所有更新都在计时器中断中。

尊敬的 Angela：

此问题是否仅在 EPWM7/8上出现？ 它是否仅在一次性加载后的下一个周期发生、还是 AQCTLA 操作从未更新？

您能否提供一些代码、以便我们能够复制我们一侧的代码？

我使用 EPWM1/2进行了简短测试、并且 AQCTL 设置更新：

//
// Included Files
//
#include "F28x_Project.h"


//
// Globals
//
uint16_t EPwm1TimerIntCount;
uint16_t EPwm2TimerIntCount;

//
// Function Prototypes
//
void InitEPwm1Example(void);
void InitEPwm2Example(void);
__interrupt void epwm1_isr(void);
__interrupt void epwm2_isr(void);
__interrupt void cpu_timer0_isr(void);

//
// Main
//
void main(void)
{
//
// Step 1. Initialize System Control:
// PLL, WatchDog, enable Peripheral Clocks
// This example function is found in the F2837xD_SysCtrl.c file.
//
    InitSysCtrl();

//
// Step 2. Initialize GPIO:
// This example function is found in the F2837xD_Gpio.c file and
// illustrates how to set the GPIO to its default state.
//
//    InitGpio();

//
// enable PWM1, PWM2
//
    CpuSysRegs.PCLKCR2.bit.EPWM1=1;
    CpuSysRegs.PCLKCR2.bit.EPWM2=1;


//
// For this case just init GPIO pins for ePWM1, ePWM2, ePWM3
// These functions are in the F2837xD_EPwm.c file
//
    InitEPwm1Gpio();
    InitEPwm2Gpio();

//
// Step 3. Clear all interrupts and initialize PIE vector table:
// Disable CPU interrupts
//
    DINT;

//
// Initialize the PIE control registers to their default state.
// The default state is all PIE interrupts disabled and flags
// are cleared.
// This function is found in the F2837xD_PieCtrl.c file.
//
    InitPieCtrl();

//
// Disable CPU interrupts and clear all CPU interrupt flags:
//
    IER = 0x0000;
    IFR = 0x0000;

//
// Initialize the PIE vector table with pointers to the shell Interrupt
// Service Routines (ISR).
// This will populate the entire table, even if the interrupt
// is not used in this example.  This is useful for debug purposes.
// The shell ISR routines are found in F2837xD_DefaultIsr.c.
// This function is found in F2837xD_PieVect.c.
//
    InitPieVectTable();
    InitCpuTimers();

//
// Interrupts that are used in this example are re-mapped to
// ISR functions found within this file.
//
    EALLOW; // This is needed to write to EALLOW protected registers
    PieVectTable.EPWM1_INT = &epwm1_isr;
    PieVectTable.EPWM2_INT = &epwm2_isr;
    PieVectTable.TIMER0_INT = &cpu_timer0_isr;
    EDIS;   // This is needed to disable write to EALLOW protected registers


//
// Configure CPU-Timer 0 to __interrupt every 500 milliseconds:
// 60MHz CPU Freq, 50 millisecond Period (in uSeconds)
//
    ConfigCpuTimer(&CpuTimer0, 60, 500000);

//
// Step 4. Initialize the Device Peripherals:
//
    EALLOW;
    CpuSysRegs.PCLKCR0.bit.TBCLKSYNC =0;
    EDIS;

    InitEPwm1Example();
    InitEPwm2Example();

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

//
// Start the timer
//
    CpuTimer0Regs.TCR.all = 0x4001;

//
// Step 5. User specific code, enable interrupts:
// Initialize counters:
//
    EPwm1TimerIntCount = 0;
    EPwm2TimerIntCount = 0;

//
// Enable CPU INT3 which is connected to EPWM1-2 INT and INT1 for Timer 0
//
    IER |= M_INT3;
    IER |= M_INT1;

//
// Enable EPWM INTn in the PIE
//
    PieCtrlRegs.PIEIER3.bit.INTx1 = 1;
    PieCtrlRegs.PIEIER3.bit.INTx2 = 1;
    PieCtrlRegs.PIEIER1.bit.INTx7 = 1;

//
// Enable global Interrupts and higher priority real-time debug events:
//
    EINT;  // Enable Global interrupt INTM
    ERTM;  // Enable Global realtime interrupt DBGM

//
// Step 6. IDLE loop. Just sit and loop forever (optional):
//
    for(;;)
    {
        asm ("          NOP");
    }
}


//
// cpu_timer0_isr - CPU Timer0 ISR
//
__interrupt void cpu_timer0_isr(void)
{
   CpuTimer0.InterruptCount++;

   //
   // Update the AQCTL settings of EPWM1 and EPWM2
   //
   EPwm1Regs.AQCTLA.bit.ZRO = AQ_CLEAR;          // Clear PWM1A on Zero
   EPwm2Regs.AQCTLA.bit.ZRO = AQ_CLEAR;          // Clear PWM1A on Zero

   // EPWM1 and EPWM2 are linked so this will udpate both
   EALLOW;
   EPwm1Regs.GLDCTL2.bit.OSHTLD = 1;               // Enable re-load of Actions
   EDIS;

   //
   // Acknowledge this __interrupt to receive more __interrupts from group 1
   //
   PieCtrlRegs.PIEACK.all = PIEACK_GROUP1;
}

//
// epwm1_isr - EPWM1 ISR
//
__interrupt void epwm1_isr(void)
{
    EPwm1TimerIntCount++;

    //
    // Clear INT flag for this timer
    //
    EPwm1Regs.ETCLR.bit.INT = 1;

    //
    // Acknowledge this interrupt to receive more interrupts from group 3
    //
    PieCtrlRegs.PIEACK.all = PIEACK_GROUP3;
}

//
// epwm2_isr - EPWM2 ISR
//
__interrupt void epwm2_isr(void)
{
    EPwm2TimerIntCount++;

    //
    // Clear INT flag for this timer
    //
    EPwm2Regs.ETCLR.bit.INT = 1;

    //
    // Acknowledge this interrupt to receive more interrupts from group 3
    //
    PieCtrlRegs.PIEACK.all = PIEACK_GROUP3;
}


//
// InitEPwm1Example - Initialize EPWM1 configuration
//
void InitEPwm1Example()
{

    //
    // Global Loading Settings
    //
    EALLOW;
    EPwm1Regs.GLDCTL.bit.GLD = 1;               // Enable Global Shadow to Active Load
    EPwm1Regs.GLDCTL.bit.GLDMODE = 1;           // Load on Counter = PRD
    EPwm1Regs.GLDCTL.bit.OSHTMODE = 1;          // One-Shot mode is active

    //
    // Global Load Parameters
    //
    EPwm1Regs.GLDCFG.bit.AQCTLA_AQCTLA2 = 1;
    EPwm1Regs.GLDCFG.bit.AQCTLB_AQCTLB2 = 1;
    EPwm1Regs.GLDCFG.bit.TBPRD_TBPRDHR = 1;
    EPwm1Regs.GLDCFG.bit.CMPA_CMPAHR = 1;
    EPwm1Regs.GLDCFG.bit.CMPB_CMPBHR = 1;
    EDIS;

    EPwm1Regs.TBPRD = 6000;                       // Set timer period
    EPwm1Regs.TBPHS.bit.TBPHS = 0x0000;           // Phase is 0
    EPwm1Regs.TBCTR = 0x0000;                     // Clear counter

    //
    // Setup TBCLK
    //
    EPwm1Regs.TBCTL.bit.CTRMODE = TB_COUNT_UP;     // Count up
    EPwm1Regs.TBCTL.bit.PHSEN = TB_DISABLE;        // Disable phase loading
    EPwm1Regs.TBCTL.bit.HSPCLKDIV = TB_DIV4;       // Clock ratio to SYSCLKOUT
    EPwm1Regs.TBCTL.bit.CLKDIV = TB_DIV4;

    //
    // Setup compare
    //
    EPwm1Regs.CMPA.bit.CMPA = 5000;
    EPwm1Regs.CMPB.bit.CMPB = 1000;

    EPwm1Regs.CMPCTL.bit.SHDWAMODE = CC_SHADOW;    // Load registers every ZERO
    EPwm1Regs.CMPCTL.bit.SHDWBMODE = CC_SHADOW;
    EPwm1Regs.CMPCTL.bit.LOADAMODE = CC_CTR_ZERO;
    EPwm1Regs.CMPCTL.bit.LOADBMODE = CC_CTR_ZERO;

    //
    // Set actions
    //
    EPwm1Regs.AQCTLA.bit.CAU = AQ_SET;            // Set PWM1A on CAU
    EPwm1Regs.AQCTLA.bit.CBU = AQ_CLEAR;          // Clear PWM1A on CBU
    EPwm1Regs.AQCTLA.bit.ZRO = AQ_SET;            // Set PWM1A on Zero

    //
    // Interrupt
    //
    EPwm1Regs.ETSEL.bit.INTSEL = ET_CTR_ZERO;    // Select INT on Zero event
    EPwm1Regs.ETSEL.bit.INTEN = 1;               // Enable INT
    EPwm1Regs.ETPS.bit.INTPRD = ET_3RD;          // Generate INT on 3rd event

    EALLOW;
    EPwm1Regs.GLDCTL2.bit.OSHTLD = 1;           // Load shadow to active for initialization
    EDIS;
}

//
// InitEPwm2Example - Initialize EPWM2 configuration
//
void InitEPwm2Example()
{

    EPwm2Regs.TBPRD = 6000;                       // Set timer period
    EPwm2Regs.TBPHS.bit.TBPHS = 0x0000;           // Phase is 0
    EPwm2Regs.TBCTR = 0x0000;                     // Clear counter

    //
    // Setup TBCLK
    //
    EPwm2Regs.TBCTL.bit.CTRMODE = TB_COUNT_UP;     // Count up
    EPwm2Regs.TBCTL.bit.PHSEN = TB_DISABLE;        // Disable phase loading
    EPwm2Regs.TBCTL.bit.HSPCLKDIV = TB_DIV4;       // Clock ratio to SYSCLKOUT
    EPwm2Regs.TBCTL.bit.CLKDIV = TB_DIV4;          // Slow just to observe on
                                                   // the scope

    //
    // Setup compare
    //
    EPwm2Regs.CMPA.bit.CMPA = 5000;
    EPwm2Regs.CMPB.bit.CMPB = 1000;

    EPwm2Regs.CMPCTL.bit.SHDWAMODE = CC_SHADOW;    // Load registers every ZERO
    EPwm2Regs.CMPCTL.bit.SHDWBMODE = CC_SHADOW;
    EPwm2Regs.CMPCTL.bit.LOADAMODE = CC_CTR_ZERO;
    EPwm2Regs.CMPCTL.bit.LOADBMODE = CC_CTR_ZERO;

    //
    // Global Loading Settings
    //
    EALLOW;
    EPwm2Regs.GLDCTL.bit.GLD = 1;               // Enable Global Shadow to Active Load
    EPwm2Regs.GLDCTL.bit.GLDMODE = 1;           // Load on Counter = PRD
    EPwm2Regs.GLDCTL.bit.OSHTMODE = 1;          // One-Shot mode is active

    //
    // Global Load Parameters
    //
    EPwm2Regs.GLDCFG.bit.AQCTLA_AQCTLA2 = 1;
    EPwm2Regs.GLDCFG.bit.AQCTLB_AQCTLB2 = 1;
    EPwm2Regs.GLDCFG.bit.TBPRD_TBPRDHR = 1;
    EPwm2Regs.GLDCFG.bit.CMPA_CMPAHR = 1;
    EPwm2Regs.GLDCFG.bit.CMPB_CMPBHR = 1;
    EDIS;

    //
    // Set actions
    //
    EPwm2Regs.AQCTLA.bit.CAU = AQ_SET;            // Set PWM2A on CAU
    EPwm2Regs.AQCTLA.bit.CBU = AQ_CLEAR;          // Clear PWM2A on CBU
    EPwm2Regs.AQCTLA.bit.ZRO = AQ_SET;            // Set PWM2A on Zero

    //
    // Interrupt
    //
    EPwm2Regs.ETSEL.bit.INTSEL = ET_CTR_ZERO;     // Select INT on Zero event
    EPwm2Regs.ETSEL.bit.INTEN = 1;                // Enable INT
    EPwm2Regs.ETPS.bit.INTPRD = ET_3RD;           // Generate INT on 3rd event


    EALLOW;
    EPwm2Regs.GLDCTL2.bit.OSHTLD = 1;           // Load shadow to active for initialization
    EDIS;

    //
    // Linking
    //
    EPwm2Regs.EPWMXLINK.bit.GLDCTL2LINK = 0;   // Link to ePWM1
    EPwm2Regs.EPWMXLINK.bit.CMPALINK = 0;      // Link to ePWM1
    EPwm2Regs.EPWMXLINK.bit.CMPBLINK = 0;      // Link to ePWM1
    EPwm2Regs.EPWMXLINK.bit.TBPRDLINK = 0;     // Link to ePWM1
}

此致、

Marlyn

您好、Marlyn、

只要在中断中更改任何 EPWM 模块的 AQCTLA、它不仅会在 EPWM7/8上以间歇间隔发生。 看起来 AQCTLA 在某个时候不会更新、并且是零星的、AQCTLA 在大多数时间通常都会更新。

很抱歉、客户无法向我们提供源代码。 但是、如果需要、它们可以提供深入的信息或进一步的测试。

你好、Nima、

黄色波形为 EPWM7_A；绿色波形为 EPWM8_A  EPWM7_A 和 EPWM8_A 是死区时间为150ns 的上桥和下桥臂驱动器。  EPWM7.EPWM8为全增模式。  

EPWM7：ZRO↑CAU↑CBU↓，EPWM7_CMPB- EPWM7_CMPA = Ton。

EPWM8：如果 CMPB > TBPRD、 ZRO↑CAU↑CBU↓，EPWM8_CMPB = EPWM8_CMPB–TBPRD；PWM8_CMPA- EPWM8_CMPB = Toff

        如果 CMPB≤TBPRD、 ZRO↓CAU↑CBU↓，EPWM8_CMPB = EPWM8_CMPB–1、 EPWM8_CMPB - EPWM8_CMPA = TOFF

所有操作 每40k 更新一次。  如果 CMPA 和 CMPB 值不正确、则应持续25us (40k)。  如下面的图1所示、如果更新成功、那么第二个 ZRO 应该被设定为低电平并且不会发生直通。  第二次 ZRO 可能仍然被设定为高电平(更新无效)并导致传递。  然后、后续波形正常(图2)

图1：

您能否捕获发生错误时的 CMPA/CMPB 值是多少？  

PRD 始终相同。

NIMA

你好、Nima、

由于开关频率太高、而且偶尔也会出现此问题、因此很难捕获 CMPA 和 CMPB。 也许我们必须使用另一种方法来找出根本原因。