ePWM

Arthur Melentovich

Hello.

I use F28M35H52C1 Concerto Control Card with dockStantion. Code Composer Studio Version: 5.5.0.00077.

Four days I tried launch PWM. And I got some result, but not finished. Help me please =(. I don't understand where I made mistake.

My scope show me next signal from PWM1A :

But I set PERIOD =1000 and DUTY_CYCLE=500.

Below I attached my code:

/*
 * main.c
 */
#include "DSP28x_Project.h"     // Device Headerfile and Examples Include File

#define  DUTY_CYCLE     500
#define  PERIOD         1000

void ConfigEpwm1( void );

int main(void)
{

	// Step 1. Initialize System Control:
	// Enable Peripheral Clocks
	// This example function is found in the F28M35x_SysCtrl.c file.
	InitSysCtrl();
	// Step 2. Initalize GPIO:
	InitEPwm1Gpio();

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

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

	    EALLOW;
	    SysCtrlRegs.PCLKCR0.bit.TBCLKSYNC = 0;       // Stop all the TB clocks
	    EDIS;

	    	ConfigEpwm1();

	    EALLOW;
	    SysCtrlRegs.PCLKCR0.bit.TBCLKSYNC = 1;        // Start all the timers synced
	    EDIS;

	    for(;;)
	    {
	        asm ("          NOP");
	    }

}

void ConfigEpwm1( void )
{
    // Assumes ePWM1 clock is already enabled in InitSysCtrl();
    EALLOW;
    // Configure PWM timers
    EPwm1Regs.TBPRD = PERIOD; // Period = 1201 TBCLK counts
    EPwm1Regs.TBPHS.half.TBPHS = 0; // Set Phase register to zero
    EPwm1Regs.TBCTL.bit.CTRMODE = TB_COUNT_UP; // Asymmetrical mode
    EPwm1Regs.TBCTL.bit.PHSEN = TB_DISABLE; // Phase loading disabled
    EPwm1Regs.TBCTL.bit.PRDLD = TB_SHADOW;
    EPwm1Regs.TBCTL.bit.SYNCOSEL = TB_SYNC_DISABLE;
    EPwm1Regs.CMPCTL.bit.SHDWAMODE = CC_SHADOW;
    EPwm1Regs.CMPCTL.bit.SHDWBMODE = CC_SHADOW;
    EPwm1Regs.CMPCTL.bit.LOADAMODE = CC_CTR_ZERO; // load on CTR=Zero
    EPwm1Regs.CMPCTL.bit.LOADBMODE = CC_CTR_ZERO; // load on CTR=Zero
    EPwm1Regs.AQCTLA.bit.PRD = AQ_CLEAR;
    EPwm1Regs.AQCTLA.bit.CAU = AQ_SET;


    //EPwm1Regs.CMPC = DUTY_CYCLE;
    EPwm1Regs.CMPA.half.CMPA=DUTY_CYCLE;

//    EPwm1Regs.ETSEL.bit.INTSEL = ET_CTR_ZERO;    // Select INT on Zero event
  //  EPwm1Regs.ETSEL.bit.INTEN = PWM1_INT_ENABLE; // Enable INT
    //EPwm1Regs.ETPS.bit.INTPRD = ET_1ST;          // Generate INT on 1st event

    EDIS;
}

And next code from M3:

int main(void)
{
    int i = 0;

    // Allow writes to protected registers.
    HWREG(SYSCTL_MWRALLOW) = 0xA5A5A5A5;

    // Sets up PLL, M3 running at 75MHz and C28 running at 150MHz
    SysCtlClockConfigSet(SYSCTL_USE_PLL | (SYSCTL_SPLLIMULT_M & 0xF) |
                         SYSCTL_SYSDIV_1 | SYSCTL_M3SSDIV_2 |
                         SYSCTL_XCLKDIV_4);

    // Enable all GPIOs
  //  PinoutSet();
    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOA);

    // Enable Pullups on EPWM(1-8)A/B capable pins
    GPIOPadConfigSet(GPIO_PORTA_BASE, 0xFF, GPIO_PIN_TYPE_STD_WPU);
//    GPIOPadConfigSet(GPIO_PORTB_BASE, 0xFF, GPIO_PIN_TYPE_STD_WPU);

    // Give C28 control of all GPIOs
    GPIOPinConfigureCoreSelect(GPIO_PORTA_BASE, 0xFF, GPIO_PIN_C_CORE_SELECT);
    // Unlock the register to change the commit register value for Port B Pin 7
    // This disables the NMI functionality on the pin and allows other muxing 
    // options to be used
    HWREG(GPIO_PORTB_BASE+GPIO_O_LOCK) = GPIO_LOCK_KEY_DD;
    // Write to commit register
    HWREG(GPIO_PORTB_BASE+GPIO_O_CR) |= 0x000000FF;
    // Delay
    for (i=0;i<20;i++){};
    IPCMtoCBootControlSystem(CBROM_MTOC_BOOTMODE_BOOT_FROM_FLASH);

    // Disable clock supply for the watchdog modules
    SysCtlPeripheralDisable(SYSCTL_PERIPH_WDOG1);
    SysCtlPeripheralDisable(SYSCTL_PERIPH_WDOG0);
    //Enable processor interrupts.
    IntMasterEnable();

    // Main Code
    while(1) ;

}

over 12 years ago

0 Gautam Iyer over 12 years ago

Guru 192875 points

Hi,

Try using this example code:

0601.epwm_adc_soc.zip

Regards,

Gautam

0 Arthur Melentovich over 12 years ago in reply to Gautam Iyer

Intellectual 475 points

Dear Gautam .

Thank you for your reply. I took this example and commented ADC and interrupt code. First, I would like get simplest PWM pulse,without ADC, interrupts etc. And got same result =( Below I attached my new code:

#include "DSP28x_Project.h"       // Device Headerfile and Examples Include File
#include <string.h>

#define  DUTY_CYCLE     50000
#define  PERIOD         100000

// Prototype statements for functions found within this file.
void ConfigEpwm1( void );

main()
{
// Step 1. Initialize System Control for Control and Analog Subsytems
// Enable Peripheral Clocks
// This example function is found in the F28M35x_SysCtrl.c file.
    InitSysCtrl();

// If project is linked into flash, copy critical code sections to RAM.
#ifdef _FLASH
   memcpy(&RamfuncsRunStart, &RamfuncsLoadStart, (size_t)&RamfuncsLoadSize);
#endif

    EDIS;

// Step 2. Initialize GPIO:
// This example function is found in the F28M35x_Gpio.c file and
// illustrates how to set the GPIO to it's default state.
// InitGpio();  // Skipped for this example
    EALLOW;
    GpioG1CtrlRegs.GPADIR.bit.GPIO0  = 1;  // Set as output
      GpioG1CtrlRegs.GPAMUX1.bit.GPIO0 = 1;  // Select EPWM1SOCA as driving source

    EDIS;

// 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 F28M35x_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 F28M35x_DefaultIsr.c.
// This function is found in F28M35x_PieVect.c.
//    InitPieVectTable();

// 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 register
//    PieVectTable.ADCINT1 = &adc1_isr;
    EDIS;   // This is needed to disable write to EALLOW protected registers

// Step 4. Initialize all the Device Peripherals:
// This function is found in F28M35x_InitPeripherals.c
// InitPeripherals(); // Not required for this example
    //InitAdc1(); // For this example, init the ADC

// Step 5. User specific code, enable interrupts:
// Enable ADCINT1 in PIE
//    PieCtrlRegs.PIEIER1.bit.INTx1 = 1;  // Enable INT 1.1 in the PIE
    IER |= M_INT1;                      // Enable CPU Interrupt 1
    EINT;                               // Enable Global interrupt INTM
    ERTM;                               // Enable Global realtime interrupt DBGM

// Configure ADC and EPWM1 sub-modules
    ConfigEpwm1();

// Wait for ADC interrupt
    for(;;)
    {

    }

}
void ConfigEpwm1( void )
{
    // Assumes ePWM1 clock is already enabled in InitSysCtrl();
    EALLOW;
    // Enable SOCA and SOCB
/*    EPwm1Regs.ETSEL.bit.SOCAEN         = 1;      // Enable SOC on A group
    EPwm1Regs.ETSEL.bit.SOCBEN         = 1;      // Enable SOC on B group
    EPwm1Regs.ETSEL.bit.SOCASEL        = 0x4;    // Select SOC from CMPA/CMPC on up count
    EPwm1Regs.ETSEL.bit.SOCBSEL        = 0x6;    // Select SOC from CMPB/CMPD on up count
    EPwm1Regs.ETSEL.bit.SOCASELCMP     = 0x1;    // CMPC
    EPwm1Regs.ETSEL.bit.SOCBSELCMP     = 0x1;    // CMPD

   EPwm1Regs.ETPS.bit.SOCAPRD         = 3;      // Generate SOCA pulse on every 3rd event
    EPwm1Regs.ETPS.bit.SOCBPRD         = 3;      // Generate SOCA pulse on every 3rd event
/**/
    // Time-base registers
    EPwm1Regs.TBPRD = PERIOD;                    // Set EPWM timer period
    EPwm1Regs.TBPHS.all = 0;                     // Time-Base Phase Register
    EPwm1Regs.TBCTR = 0;                         // Time-Base Counter Register
    EPwm1Regs.TBCTL.bit.PRDLD = TB_IMMEDIATE;    // Set Immediate load
    EPwm1Regs.TBCTL.bit.CTRMODE = TB_COUNT_UP;   // Count-up mode: used for asymmetric PWM

    EPwm1Regs.TBCTL.bit.PHSEN = TB_DISABLE;      // Disable phase loading
    EPwm1Regs.TBCTL.bit.SYNCOSEL = TB_SYNC_DISABLE;

    // Set TBCLK frequency
    EPwm1Regs.TBCTL.bit.HSPCLKDIV = TB_DIV1;     // TBCLK = SYSCLKOUT
    EPwm1Regs.TBCTL.bit.CLKDIV = TB_DIV1;

    // Setup shadow register load on ZERO
    EPwm1Regs.CMPCTL.bit.SHDWAMODE = CC_SHADOW;
    EPwm1Regs.CMPCTL.bit.SHDWBMODE = CC_SHADOW;
    EPwm1Regs.CMPCTL.bit.LOADAMODE = CC_CTR_ZERO; // load on CTR=Zero
    EPwm1Regs.CMPCTL.bit.LOADBMODE = CC_CTR_ZERO; // load on CTR=Zero

    // Set Compare values
    EPwm1Regs.CMPC = DUTY_CYCLE;
    EPwm1Regs.CMPD = DUTY_CYCLE;
    EDIS;
}

0 Arthur Melentovich over 12 years ago in reply to Arthur Melentovich

Intellectual 475 points

I got correct signal with one example.... tomorrow I'll trying to understand why it wasn't working =) ... I'm thinking it was troubles with debugging mode, but not sure.

0 Gautam Iyer over 12 years ago in reply to Arthur Melentovich

Guru 192875 points

Hi Arthur,

The code attached above was for ADC SOC than for generating ePWM. Her's the code for ePWM generation:

Fullscreen 1602.epwm_updown_aq_c28.c Download

//###########################################################################
// FILE:   epwm_updown_aq_c28.c
// TITLE:  Action Qualifier Module - Using up/down count.
//
//! \addtogroup control_example_list
//! <h1> EPWM Action Qualifier (epwm_updown_aq)</h1>
//!
//! This example configures ePWM1, ePWM2, ePWM3 to produce an
//! waveform with independant modulation on EPWMxA and
//! EPWMxB.
//!
//! The compare values CMPA and CMPB are modified within the ePWM's ISR.
//!
//! The TB counter is in up/down count mode for this example.
//!
//! View the EPWM1A/B(PA0_GPIO0 & PA1_GPIO1), EPWM2A/B(PA2_GPIO2 & PA3_GPIO3)
//! and EPWM3A/B(PA4_GPIO4 & PA5_GPIO5) waveforms via an oscilloscope.
//
//###########################################################################
// $TI Release: F28M35x Support Library v201 $
// $Release Date: Fri Jun  7 10:51:13 CDT 2013 $
//###########################################################################

#include "DSP28x_Project.h"     // Device Headerfile and Examples Include File

typedef struct
{
    volatile struct EPWM_REGS *EPwmRegHandle;
    Uint16 EPwm_CMPA_Direction;
    Uint16 EPwm_CMPB_Direction;
    Uint16 EPwmTimerIntCount;
    Uint16 EPwmMaxCMPA;
    Uint16 EPwmMinCMPA;
    Uint16 EPwmMaxCMPB;
    Uint16 EPwmMinCMPB;
}EPWM_INFO;

// Prototype statements for functions found within this file.
void InitEPwm1Example(void);
void InitEPwm2Example(void);
void InitEPwm3Example(void);
__interrupt void epwm1_isr(void);
__interrupt void epwm2_isr(void);
__interrupt void epwm3_isr(void);
void update_compare(EPWM_INFO*);

// Global variables used in this example
EPWM_INFO epwm1_info;
EPWM_INFO epwm2_info;
EPWM_INFO epwm3_info;

// Configure the period for each timer
#define EPWM1_TIMER_TBPRD  2000  // Period register
#define EPWM1_MAX_CMPA     1950
#define EPWM1_MIN_CMPA       50
#define EPWM1_MAX_CMPB     1950
#define EPWM1_MIN_CMPB       50

#define EPWM2_TIMER_TBPRD  2000  // Period register
#define EPWM2_MAX_CMPA     1950
#define EPWM2_MIN_CMPA       50
#define EPWM2_MAX_CMPB     1950
#define EPWM2_MIN_CMPB       50

#define EPWM3_TIMER_TBPRD  2000  // Period register
#define EPWM3_MAX_CMPA      950
#define EPWM3_MIN_CMPA       50
#define EPWM3_MAX_CMPB     1950
#define EPWM3_MIN_CMPB     1050

// To keep track of which way the compare value is moving
#define EPWM_CMP_UP   1
#define EPWM_CMP_DOWN 0

void main(void)
{
// Step 1. Initialize System Control:
// Enable Peripheral Clocks
// This example function is found in the F28M35x_SysCtrl.c file.
    InitSysCtrl();

// Step 2. Initalize GPIO:
// This example function is found in the F28M35x_Gpio.c file and
// illustrates how to set the GPIO to it's default state.
// InitGpio();  // Skipped for this example

// For this case just init GPIO pins for ePWM1, ePWM2, ePWM3
// These functions are in the F28M35x_EPwm.c file
    InitEPwm1Gpio();
    InitEPwm2Gpio();
    InitEPwm3Gpio();

// 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 F28M35x_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 F28M35x_DefaultIsr.c.
// This function is found in F28M35x_PieVect.c.
    InitPieVectTable();

// 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.EPWM3_INT = &epwm3_isr;
    EDIS;   // This is needed to disable write to EALLOW protected registers

// Step 4. Initialize all the Device Peripherals:
// This function is found in F28M35x_InitPeripherals.c
// InitPeripherals();  // Not required for this example

// For this example, only initialize the ePWM

    EALLOW;
    SysCtrlRegs.PCLKCR0.bit.TBCLKSYNC = 0;
    EDIS;

    InitEPwm1Example();
    InitEPwm2Example();
    InitEPwm3Example();

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

// Step 5. User specific code, enable interrupts:

// Enable CPU INT3 which is connected to EPWM1-3 INT:
    IER |= M_INT3;

// Enable EPWM INTn in the PIE: Group 3 interrupt 1-3
    PieCtrlRegs.PIEIER3.bit.INTx1 = 1;
    PieCtrlRegs.PIEIER3.bit.INTx2 = 1;
    PieCtrlRegs.PIEIER3.bit.INTx3 = 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");
    }

}

__interrupt void epwm1_isr(void)
{
    // Update the CMPA and CMPB values
    update_compare(&epwm1_info);

    // 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;
}

__interrupt void epwm2_isr(void)
{

    // Update the CMPA and CMPB values
    update_compare(&epwm2_info);

    // 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;
}

__interrupt void epwm3_isr(void)
{

    // Update the CMPA and CMPB values
    update_compare(&epwm3_info);

    // Clear INT flag for this timer
    EPwm3Regs.ETCLR.bit.INT = 1;

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

void InitEPwm1Example()
{

    // Setup TBCLK
    EPwm1Regs.TBPRD = EPWM1_TIMER_TBPRD;          // Set timer period 801 TBCLKs
    EPwm1Regs.TBPHS.half.TBPHS = 0x0000;          // Phase is 0
    EPwm1Regs.TBCTR = 0x0000;                     // Clear counter

    // Set Compare values
    EPwm1Regs.CMPA.half.CMPA = EPWM1_MIN_CMPA;    // Set compare A value
    EPwm1Regs.CMPB = EPWM1_MAX_CMPB;              // Set Compare B value

    // Setup counter mode
    EPwm1Regs.TBCTL.bit.CTRMODE = TB_COUNT_UPDOWN; // Count up
    EPwm1Regs.TBCTL.bit.PHSEN = TB_DISABLE;       // Disable phase loading
    EPwm1Regs.TBCTL.bit.HSPCLKDIV = TB_DIV1;      // Clock ratio to SYSCLKOUT
    EPwm1Regs.TBCTL.bit.CLKDIV = TB_DIV1;

    // Setup shadowing
    EPwm1Regs.CMPCTL.bit.SHDWAMODE = CC_SHADOW;
    EPwm1Regs.CMPCTL.bit.SHDWBMODE = CC_SHADOW;
    EPwm1Regs.CMPCTL.bit.LOADAMODE = CC_CTR_ZERO; // Load on Zero
    EPwm1Regs.CMPCTL.bit.LOADBMODE = CC_CTR_ZERO;

    // Set actions
    EPwm1Regs.AQCTLA.bit.CAU = AQ_SET;            // Set PWM1A on event A, up
                                                  // count
    EPwm1Regs.AQCTLA.bit.CAD = AQ_CLEAR;          // Clear PWM1A on event A,
                                                  // down count

    EPwm1Regs.AQCTLB.bit.CBU = AQ_SET;            // Set PWM1B on event B, up
                                                  // count
    EPwm1Regs.AQCTLB.bit.CBD = AQ_CLEAR;          // Clear PWM1B on event B,
                                                  // down count

    // Interrupt where we will change the Compare Values
    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

    // Information this example uses to keep track
    // of the direction the CMPA/CMPB values are
    // moving, the min and max allowed values and
    // a pointer to the correct ePWM registers
    epwm1_info.EPwm_CMPA_Direction = EPWM_CMP_UP;  // Start by increasing CMPA &
    epwm1_info.EPwm_CMPB_Direction = EPWM_CMP_DOWN; // decreasing CMPB
    epwm1_info.EPwmTimerIntCount = 0;              // Zero the interrupt counter
    epwm1_info.EPwmRegHandle = &EPwm1Regs;         // Set the pointer to the
                                                   // ePWM module
    epwm1_info.EPwmMaxCMPA = EPWM1_MAX_CMPA;       // Setup min/max CMPA/CMPB
                                                   // values
    epwm1_info.EPwmMinCMPA = EPWM1_MIN_CMPA;
    epwm1_info.EPwmMaxCMPB = EPWM1_MAX_CMPB;
    epwm1_info.EPwmMinCMPB = EPWM1_MIN_CMPB;

}

void InitEPwm2Example()
{

    // Setup TBCLK
    EPwm2Regs.TBPRD = EPWM2_TIMER_TBPRD;          // Set timer period 801 TBCLKs
    EPwm2Regs.TBPHS.half.TBPHS = 0x0000;          // Phase is 0
    EPwm2Regs.TBCTR = 0x0000;                     // Clear counter

    // Set Compare values
    EPwm2Regs.CMPA.half.CMPA = EPWM2_MIN_CMPA;    // Set compare A value
    EPwm2Regs.CMPB = EPWM2_MIN_CMPB;              // Set Compare B value

    // Setup counter mode
    EPwm2Regs.TBCTL.bit.CTRMODE = TB_COUNT_UPDOWN; // Count up
    EPwm2Regs.TBCTL.bit.PHSEN = TB_DISABLE;       // Disable phase loading
    EPwm2Regs.TBCTL.bit.HSPCLKDIV = TB_DIV1;      // Clock ratio to SYSCLKOUT
    EPwm2Regs.TBCTL.bit.CLKDIV = TB_DIV1;

    // Setup shadowing
    EPwm2Regs.CMPCTL.bit.SHDWAMODE = CC_SHADOW;
    EPwm2Regs.CMPCTL.bit.SHDWBMODE = CC_SHADOW;
    EPwm2Regs.CMPCTL.bit.LOADAMODE = CC_CTR_ZERO; // Load on Zero
    EPwm2Regs.CMPCTL.bit.LOADBMODE = CC_CTR_ZERO;

    // Set actions
    EPwm2Regs.AQCTLA.bit.CAU = AQ_SET;           // Set PWM2A on event A, up
                                                 // count
    EPwm2Regs.AQCTLA.bit.CBD = AQ_CLEAR;         // Clear PWM2A on event B, down
                                                 // count

    EPwm2Regs.AQCTLB.bit.ZRO = AQ_CLEAR;         // Clear PWM2B on zero
    EPwm2Regs.AQCTLB.bit.PRD = AQ_SET  ;         // Set PWM2B on period

    // 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_3RD;          // Generate INT on 3rd event

    // Information this example uses to keep track
    // of the direction the CMPA/CMPB values are
    // moving, the min and max allowed values and
    // a pointer to the correct ePWM registers
    epwm2_info.EPwm_CMPA_Direction = EPWM_CMP_UP;  // Start by increasing CMPA &
    epwm2_info.EPwm_CMPB_Direction = EPWM_CMP_UP;  // increasing CMPB
    epwm2_info.EPwmTimerIntCount = 0;              // Zero the interrupt counter
    epwm2_info.EPwmRegHandle = &EPwm2Regs;         // Set the pointer to the
                                                   // ePWM module
    epwm2_info.EPwmMaxCMPA = EPWM2_MAX_CMPA;       // Setup min/max CMPA/CMPB
                                                   // values
    epwm2_info.EPwmMinCMPA = EPWM2_MIN_CMPA;
    epwm2_info.EPwmMaxCMPB = EPWM2_MAX_CMPB;
    epwm2_info.EPwmMinCMPB = EPWM2_MIN_CMPB;

}

void InitEPwm3Example(void)
{

    // Setup TBCLK
    EPwm3Regs.TBCTL.bit.CTRMODE = TB_COUNT_UPDOWN; // Count up/down
    EPwm3Regs.TBPRD = EPWM3_TIMER_TBPRD;         // Set timer period
    EPwm3Regs.TBCTL.bit.PHSEN = TB_DISABLE;      // Disable phase loading
    EPwm3Regs.TBPHS.half.TBPHS = 0x0000;         // Phase is 0
    EPwm3Regs.TBCTR = 0x0000;                    // Clear counter
    EPwm3Regs.TBCTL.bit.HSPCLKDIV = TB_DIV1;     // Clock ratio to SYSCLKOUT
    EPwm3Regs.TBCTL.bit.CLKDIV = TB_DIV1;

    // Setup shadow register load on ZERO
    EPwm3Regs.CMPCTL.bit.SHDWAMODE = CC_SHADOW;
    EPwm3Regs.CMPCTL.bit.SHDWBMODE = CC_SHADOW;
    EPwm3Regs.CMPCTL.bit.LOADAMODE = CC_CTR_ZERO;
    EPwm3Regs.CMPCTL.bit.LOADBMODE = CC_CTR_ZERO;

    // Set Compare values
    EPwm3Regs.CMPA.half.CMPA = EPWM3_MIN_CMPA;   // Set compare A value
    EPwm3Regs.CMPB = EPWM3_MAX_CMPB;             // Set Compare B value

    // Set Actions
    EPwm3Regs.AQCTLA.bit.PRD = AQ_SET;           // Set PWM3A on period
    EPwm3Regs.AQCTLA.bit.CBD = AQ_CLEAR;         // Clear PWM3A on event B, down
                                                 // count

    EPwm3Regs.AQCTLB.bit.PRD = AQ_CLEAR;         // Clear PWM3A on period
    EPwm3Regs.AQCTLB.bit.CAU = AQ_SET;           // Set PWM3A on event A, up
                                                 // count

    // 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_3RD;          // Generate INT on 3rd event

    // Information this example uses to keep track
    // of the direction the CMPA/CMPB values are
    // moving, the min and max allowed values and
    // a pointer to the correct ePWM registers
    epwm3_info.EPwm_CMPA_Direction = EPWM_CMP_UP;  // Start by increasing CMPA &
    epwm3_info.EPwm_CMPB_Direction = EPWM_CMP_DOWN; // decreasing CMPB
    epwm3_info.EPwmTimerIntCount = 0;              // Zero the interrupt counter
    epwm3_info.EPwmRegHandle = &EPwm3Regs;         // Set the pointer to the
                                                   // ePWM module
    epwm3_info.EPwmMaxCMPA = EPWM3_MAX_CMPA;       // Setup min/max CMPA/CMPB
                                                   // values
    epwm3_info.EPwmMinCMPA = EPWM3_MIN_CMPA;
    epwm3_info.EPwmMaxCMPB = EPWM3_MAX_CMPB;
    epwm3_info.EPwmMinCMPB = EPWM3_MIN_CMPB;

}

void update_compare(EPWM_INFO *epwm_info)
{

    // Every 10'th interrupt, change the CMPA/CMPB values
    if(epwm_info->EPwmTimerIntCount == 10)
    {
        epwm_info->EPwmTimerIntCount = 0;

        // If we were increasing CMPA, check to see if
        // we reached the max value.  If not, increase CMPA
        // else, change directions and decrease CMPA
        if(epwm_info->EPwm_CMPA_Direction == EPWM_CMP_UP)
        {
            if(epwm_info->EPwmRegHandle->CMPA.half.CMPA <
               epwm_info->EPwmMaxCMPA)
            {
                epwm_info->EPwmRegHandle->CMPA.half.CMPA++;
            }
            else
            {
                epwm_info->EPwm_CMPA_Direction = EPWM_CMP_DOWN;
                epwm_info->EPwmRegHandle->CMPA.half.CMPA--;
            }
        }

        // If we were decreasing CMPA, check to see if
        // we reached the min value.  If not, decrease CMPA
        // else, change directions and increase CMPA
        else
        {
            if(epwm_info->EPwmRegHandle->CMPA.half.CMPA ==
               epwm_info->EPwmMinCMPA)
            {
                epwm_info->EPwm_CMPA_Direction = EPWM_CMP_UP;
                epwm_info->EPwmRegHandle->CMPA.half.CMPA++;
            }
            else
            {
                epwm_info->EPwmRegHandle->CMPA.half.CMPA--;
            }
        }

        // If we were increasing CMPB, check to see if
        // we reached the max value.  If not, increase CMPB
        // else, change directions and decrease CMPB
        if(epwm_info->EPwm_CMPB_Direction == EPWM_CMP_UP)
        {
            if(epwm_info->EPwmRegHandle->CMPB < epwm_info->EPwmMaxCMPB)
            {
                epwm_info->EPwmRegHandle->CMPB++;
            }
            else
            {
                epwm_info->EPwm_CMPB_Direction = EPWM_CMP_DOWN;
                epwm_info->EPwmRegHandle->CMPB--;
            }
        }

        // If we were decreasing CMPB, check to see if
        // we reached the min value.  If not, decrease CMPB
        // else, change directions and increase CMPB

        else
        {
            if(epwm_info->EPwmRegHandle->CMPB == epwm_info->EPwmMinCMPB)
            {
                epwm_info->EPwm_CMPB_Direction = EPWM_CMP_UP;
                epwm_info->EPwmRegHandle->CMPB++;
            }
            else
            {
                epwm_info->EPwmRegHandle->CMPB--;
            }
        }
    }
    else
    {
        epwm_info->EPwmTimerIntCount++;
    }

    return;
}

Regards,

Gautam

0 Arthur Melentovich over 12 years ago in reply to Gautam Iyer

Intellectual 475 points

I've done with PWM without any interrupts, ADC etc. Problem was in the working with two core in the debug mode. I still don't good understand how launch debug with two core. But simplest PWM is working. Gautam, thank you very much for your attendance and advice.

Regards.

0 Gautam Iyer over 12 years ago in reply to Arthur Melentovich

Guru 192875 points

That's great. For debugging 2 cores check this out:

http://e2e.ti.com/support/microcontrollers/c2000/f/171/t/166587.aspx

Good luck, Merry Christmas & Regards,

Gautam

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