F28335 EPWM to GPIO

Fasil Mohamed

Other Parts Discussed in Thread: CONTROLSUITE

Hi,

I am a new user of f28335. I am using ADC SOC example. I would like to know how to set the period of EPWM. I need the input to be sampled at 0.01ms. Also please provide me another program in which the epwm output can be seen on the gpio pin for ADC SOC example. Please answer me.

Regards,

Fasil

over 9 years ago

0 Gautam Iyer over 9 years ago

Guru 192875 points

Hi Fasil,

TBPRD is the period register. Also, if you go through the ePWM user guide you can get the formula used to calculate the same:

Regards,

Gautam

0 Fasil Mohamed over 9 years ago in reply to Gautam Iyer

Intellectual 265 points

thanks for your reply.

How much does 1 TTBCLKmeasure?
I need a sampling period of 0.01 ms. Is it ok if i put TBPRD = 0009?
Regards,
Fasil

0 Gautam Iyer over 9 years ago in reply to Fasil Mohamed

Guru 192875 points

TBCLK frequency = SYSCLK/4 = 150MHz/4 = 37.5MHz

Ttbclk = (1/37.5M)sec

Check TBCTL register's CLKDIV field for the same!

Regards,
Gautam

0 Fasil Mohamed over 9 years ago in reply to Gautam Iyer

Intellectual 265 points

how can we find epwm output of adcsoc example through gpio?

Regards,
Fasil

0 Gautam Iyer over 9 years ago in reply to Fasil Mohamed

Guru 192875 points

By connecting ePWM1a pin output to DSO.

0 Fasil Mohamed over 9 years ago in reply to Gautam Iyer

Intellectual 265 points

Does it require any editing in the example?

This is the example code:

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

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

// Global variables used in this example:
Uint16 LoopCount;
Uint16 ConversionCount;
Uint16 Voltage1[10];
Uint16 Voltage2[10];

main()
{

// Step 1. Initialize System Control:
// PLL, WatchDog, enable Peripheral Clocks
// This example function is found in the DSP2833x_SysCtrl.c file.
InitSysCtrl();

EALLOW;
#if (CPU_FRQ_150MHZ) // Default - 150 MHz SYSCLKOUT
#define ADC_MODCLK 0x3 // HSPCLK = SYSCLKOUT/2*ADC_MODCLK2 = 150/(2*3) = 25.0 MHz
#endif
#if (CPU_FRQ_100MHZ)
#define ADC_MODCLK 0x2 // HSPCLK = SYSCLKOUT/2*ADC_MODCLK2 = 100/(2*2) = 25.0 MHz
#endif
EDIS;

// Step 2. Initialize GPIO:
// This example function is found in the DSP2833x_Gpio.c file and
// illustrates how to set the GPIO to it's default state.
// InitGpio(); // Skipped for this example

// 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 DSP2833x_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 DSP2833x_DefaultIsr.c.
// This function is found in DSP2833x_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.ADCINT = &adc_isr;
EDIS; // This is needed to disable write to EALLOW protected registers

// Step 4. Initialize all the Device Peripherals:
// This function is found in DSP2833x_InitPeripherals.c
// InitPeripherals(); // Not required for this example
InitAdc(); // For this example, init the ADC

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

// Enable ADCINT in PIE
PieCtrlRegs.PIEIER1.bit.INTx6 = 1;
IER |= M_INT1; // Enable CPU Interrupt 1
EINT; // Enable Global interrupt INTM
ERTM; // Enable Global realtime interrupt DBGM

LoopCount = 0;
ConversionCount = 0;

// Configure ADC
AdcRegs.ADCMAXCONV.all = 0x0001; // Setup 2 conv's on SEQ1
AdcRegs.ADCCHSELSEQ1.bit.CONV00 = 0x3; // Setup ADCINA3 as 1st SEQ1 conv.
AdcRegs.ADCCHSELSEQ1.bit.CONV01 = 0x2; // Setup ADCINA2 as 2nd SEQ1 conv.
AdcRegs.ADCTRL2.bit.EPWM_SOCA_SEQ1 = 1;// Enable SOCA from ePWM to start SEQ1
AdcRegs.ADCTRL2.bit.INT_ENA_SEQ1 = 1; // Enable SEQ1 interrupt (every EOS)

// Assumes ePWM1 clock is already enabled in InitSysCtrl();
EPwm1Regs.ETSEL.bit.SOCAEN = 1; // Enable SOC on A group
EPwm1Regs.ETSEL.bit.SOCASEL = 4; // Select SOC from from CPMA on upcount
EPwm1Regs.ETPS.bit.SOCAPRD = 1; // Generate pulse on 1st event
EPwm1Regs.CMPA.half.CMPA = 0x0080; // Set compare A value
EPwm1Regs.TBPRD = 0xFFFF; // Set period for ePWM1
EPwm1Regs.TBCTL.bit.CTRMODE = 0; // count up and start

// Wait for ADC interrupt
for(;;)
{
LoopCount++;
}
}
interrupt void adc_isr(void)
{

Voltage1[ConversionCount] = AdcRegs.ADCRESULT0 >>4;
Voltage2[ConversionCount] = AdcRegs.ADCRESULT1 >>4;

// If 40 conversions have been logged, start over
if(ConversionCount == 9)
{
ConversionCount = 0;
}
else ConversionCount++;

// Reinitialize for next ADC sequence
AdcRegs.ADCTRL2.bit.RST_SEQ1 = 1; // Reset SEQ1
AdcRegs.ADCST.bit.INT_SEQ1_CLR = 1; // Clear INT SEQ1 bit
PieCtrlRegs.PIEACK.all = PIEACK_GROUP1; // Acknowledge interrupt to PIE

return;
}

0 Gautam Iyer over 9 years ago in reply to Fasil Mohamed

Guru 192875 points

You don't have to edit the example code at all. You can connect DSO probe directly to configured ePWM outputs.

0 Fasil Mohamed over 9 years ago in reply to Gautam Iyer

Intellectual 265 points

But it didn't show any output. Does it require additional code in the example for configuring pwm output?

0 Fasil Mohamed over 9 years ago in reply to Fasil Mohamed

Intellectual 265 points

my new code:

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

// Prototype statements for functions found within this file.
interrupt void adc_isr(void);
void Gpio_select(void);
// Global variables used in this example:
Uint16 LoopCount;
Uint16 ConversionCount;
Uint16 Voltage1[2000];

main()
{

// Step 1. Initialize System Control:
// PLL, WatchDog, enable Peripheral Clocks
// This example function is found in the DSP2833x_SysCtrl.c file.
InitSysCtrl();

Gpio_select();

EALLOW;
#if (CPU_FRQ_150MHZ) // Default - 150 MHz SYSCLKOUT
#define ADC_MODCLK 0x3 // HSPCLK = SYSCLKOUT/2*ADC_MODCLK2 = 150/(2*3) = 25.0 MHz
#endif
#if (CPU_FRQ_100MHZ)
#define ADC_MODCLK 0x2 // HSPCLK = SYSCLKOUT/2*ADC_MODCLK2 = 100/(2*2) = 25.0 MHz
#endif
EDIS;

// Step 2. Initialize GPIO:
// This example function is found in the DSP2833x_Gpio.c file and
// illustrates how to set the GPIO to it's default state.
// InitGpio(); // Skipped for this example

// 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 DSP2833x_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 DSP2833x_DefaultIsr.c.
// This function is found in DSP2833x_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.ADCINT = &adc_isr;
EDIS; // This is needed to disable write to EALLOW protected registers

// Step 4. Initialize all the Device Peripherals:
// This function is found in DSP2833x_InitPeripherals.c
// InitPeripherals(); // Not required for this example
InitAdc(); // For this example, init the ADC

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

// Enable ADCINT in PIE
PieCtrlRegs.PIEIER1.bit.INTx6 = 1;
IER |= M_INT1; // Enable CPU Interrupt 1
EINT; // Enable Global interrupt INTM
ERTM; // Enable Global realtime interrupt DBGM

LoopCount = 0;
ConversionCount = 0;

// Configure ADC
AdcRegs.ADCMAXCONV.all = 0x0000; // Setup 2 conv's on SEQ1
AdcRegs.ADCCHSELSEQ1.bit.CONV00 = 0x3; // Setup ADCINA3 as 1st SEQ1 conv.

AdcRegs.ADCTRL2.bit.EPWM_SOCA_SEQ1 = 1;// Enable SOCA from ePWM to start SEQ1
AdcRegs.ADCTRL2.bit.INT_ENA_SEQ1 = 1; // Enable SEQ1 interrupt (every EOS)

// Assumes ePWM1 clock is already enabled in InitSysCtrl();
EPwm1Regs.ETSEL.bit.SOCAEN = 1; // Enable SOC on A group
EPwm1Regs.ETSEL.bit.SOCASEL = 4; // Select SOC from from CPMA on upcount
EPwm1Regs.ETPS.bit.SOCAPRD = 1; // Generate pulse on 1st event
EPwm1Regs.CMPA.half.CMPA = 0x0000; // Set compare A value
EPwm1Regs.TBPRD = 0x0009; // Set period for ePWM1
EPwm1Regs.TBCTL.bit.CTRMODE = 0; // count up and start

// Wait for ADC interrupt
for(;;)
{
LoopCount++;
}
}
interrupt void adc_isr(void)
{

Voltage1[ConversionCount] = AdcRegs.ADCRESULT0 >>4;

// If 40 conversions have been logged, start over
if(ConversionCount == 1999)
{
ConversionCount = 0;
}
else ConversionCount++;

// Reinitialize for next ADC sequence
AdcRegs.ADCTRL2.bit.RST_SEQ1 = 1; // Reset SEQ1
AdcRegs.ADCST.bit.INT_SEQ1_CLR = 1; // Clear INT SEQ1 bit
PieCtrlRegs.PIEACK.all = PIEACK_GROUP1; // Acknowledge interrupt to PIE

return;

}

void Gpio_select(void)

{

EALLOW;
GpioCtrlRegs.GPAMUX1.all = 0x00000000; // All GPIO
GpioCtrlRegs.GPAMUX2.all = 0x00000000; // All GPIO
GpioCtrlRegs.GPAMUX1.all = 0x00000000; // All GPIO
GpioCtrlRegs.GPADIR.all = 0xFFFFFFFF; // All outputs
GpioCtrlRegs.GPBDIR.all = 0x0000000F; // All outputs
EDIS;

}

0 Gautam Iyer over 9 years ago in reply to Fasil Mohamed

Guru 192875 points

Try this example: C:\ti\controlSUITE\device_support\f2833x\v140\DSP2833x_examples_ccsv5\epwm_up_aq

0 Fasil Mohamed over 9 years ago in reply to Gautam Iyer

Intellectual 265 points

See this program:If I connect GPIO0 to DSO, I am not getting any output. What should I do in this program to get an EPWM1 output.? otherwise can you please edit the program to get epwm for 0.01ms?

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

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

// Global variables used in this example:
Uint16 LoopCount;
Uint16 ConversionCount;
Uint16 Voltage1[2000];

main()
{

// Step 1. Initialize System Control:
// PLL, WatchDog, enable Peripheral Clocks
// This example function is found in the DSP2833x_SysCtrl.c file.
InitSysCtrl();

// Step 2. Initialize GPIO:
// This example function is found in the DSP2833x_Gpio.c file and
// illustrates how to set the GPIO to it's default state.
// InitGpio(); // Skipped for this example

// 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;

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

// Enable ADCINT in PIE
PieCtrlRegs.PIEIER1.bit.INTx6 = 1;
IER |= M_INT1; // Enable CPU Interrupt 1
EINT; // Enable Global interrupt INTM
ERTM; // Enable Global realtime interrupt DBGM

LoopCount = 0;
ConversionCount = 0;

// Configure ADC
AdcRegs.ADCMAXCONV.all = 0x0000; // Setup 2 conv's on SEQ1
AdcRegs.ADCCHSELSEQ1.bit.CONV00 = 0x3; // Setup ADCINA3 as 1st SEQ1 conv.

AdcRegs.ADCTRL2.bit.EPWM_SOCA_SEQ1 = 1;// Enable SOCA from ePWM to start SEQ1
AdcRegs.ADCTRL2.bit.INT_ENA_SEQ1 = 1; // Enable SEQ1 interrupt (every EOS)

// Assumes ePWM1 clock is already enabled in InitSysCtrl();
EPwm1Regs.ETSEL.bit.SOCAEN = 1; // Enable SOC on A group
EPwm1Regs.ETSEL.bit.SOCASEL = 4; // Select SOC from from CPMA on upcount
EPwm1Regs.ETPS.bit.SOCAPRD = 1; // Generate pulse on 1st event
EPwm1Regs.CMPA.half.CMPA = 0x0000; // Set compare A value
EPwm1Regs.TBPRD = 0x0009; // Set period for ePWM1
EPwm1Regs.TBCTL.bit.CTRMODE = 0; // count up and start

// Wait for ADC interrupt
for(;;)
{
LoopCount++;
}
}
interrupt void adc_isr(void)
{

Voltage1[ConversionCount] = AdcRegs.ADCRESULT0 >>4;

// If 40 conversions have been logged, start over
if(ConversionCount == 1999)
{
ConversionCount = 0;
}
else ConversionCount++;

return;

}

0 Fasil Mohamed over 9 years ago in reply to Fasil Mohamed

Intellectual 265 points

I got the program. Thanks for your help. :-D

Fasil

0 Gautam Iyer over 9 years ago in reply to Fasil Mohamed

Guru 192875 points

You're Welcome! Please close the thread by verifying the answer.

Goodluck & Regards,
Gautam

0 Jitendra nama over 8 years ago in reply to Gautam Iyer

Prodigy 90 points

Sir i am having same problem there is no output at epwm

my code is here

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

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

// Global variables used in this example:
Uint16 LoopCount;
Uint16 ConversionCount;

main()
{
// Step 1. Initialize System Control:
// PLL, WatchDog, enable Peripheral Clocks
// This example function is found in the DSP2833x_SysCtrl.c file.
InitSysCtrl();

EALLOW;
#if (CPU_FRQ_150MHZ) // Default - 150 MHz SYSCLKOUT
#define ADC_MODCLK 0x3 // HSPCLK = SYSCLKOUT/2*ADC_MODCLK2 = 150/(2*3) = 25.0 MHz
#endif
#if (CPU_FRQ_100MHZ)
#define ADC_MODCLK 0x2 // HSPCLK = SYSCLKOUT/2*ADC_MODCLK2 = 100/(2*2) = 25.0 MHz
#endif
EDIS;

// Define ADCCLK clock frequency ( less than or equal to 25 MHz )
// Assuming InitSysCtrl() has set SYSCLKOUT to 150 MHz
EALLOW;
SysCtrlRegs.HISPCP.all = ADC_MODCLK;
EDIS;

// Step 2. Initialize GPIO:
// This example function is found in the DSP2833x_Gpio.c file and
// illustrates how to set the GPIO to it's default state.
// InitGpio(); // Skipped for this example

// 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 DSP2833x_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 DSP2833x_DefaultIsr.c.
// This function is found in DSP2833x_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.ADCINT = &adc_isr;
EDIS; // This is needed to disable write to EALLOW protected registers

// Step 4. Initialize all the Device Peripherals:
// This function is found in DSP2833x_InitPeripherals.c
// InitPeripherals(); // Not required for this example
InitAdc(); // For this example, init the ADC

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

// Enable ADCINT in PIE
PieCtrlRegs.PIEIER1.bit.INTx6 = 1;
IER |= M_INT1; // Enable CPU Interrupt 1
EINT; // Enable Global interrupt INTM
ERTM; // Enable Global realtime interrupt DBGM

LoopCount = 0;
ConversionCount = 0;

// Configure ADC
AdcRegs.ADCMAXCONV.all = 0x0001; // Setup 2 conv's on SEQ1
AdcRegs.ADCCHSELSEQ1.bit.CONV00 = 0x3; // Setup ADCINA3 as 1st SEQ1 conv.
AdcRegs.ADCCHSELSEQ1.bit.CONV01 = 0x2; // Setup ADCINA2 as 2nd SEQ1 conv.
AdcRegs.ADCTRL2.bit.EPWM_SOCA_SEQ1 = 1;// Enable SOCA from ePWM to start SEQ1
AdcRegs.ADCTRL2.bit.INT_ENA_SEQ1 = 1; // Enable SEQ1 interrupt (every EOS)

// Assumes ePWM1 clock is already enabled in InitSysCtrl();
EPwm1Regs.TBPRD = 15000; // 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 = 0x0080; // Set compare A value
EPwm1Regs.CMPB = 0x0080; // 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

EPwm1Regs.ETSEL.bit.SOCAEN = 1; // Enable SOC on A group
EPwm1Regs.ETSEL.bit.SOCASEL = 4; // Select SOC from from CPMA on upcount
EPwm1Regs.ETPS.bit.SOCAPRD = 1; // Generate pulse on 1st event

// Wait for ADC interrupt
for(;;)
{
LoopCount++;
}
}

__interrupt void adc_isr(void)
{

EPwm1Regs.CMPA.half.CMPA = 3*AdcRegs.ADCRESULT0; // Set compare A value
EPwm1Regs.CMPB = AdcRegs.ADCRESULT1;

// If 40 conversions have been logged, start over
if(ConversionCount == 9)
{
ConversionCount = 0;
}
else
{
ConversionCount++;
}

// Reinitialize for next ADC sequence
AdcRegs.ADCTRL2.bit.RST_SEQ1 = 1; // Reset SEQ1
AdcRegs.ADCST.bit.INT_SEQ1_CLR = 1; // Clear INT SEQ1 bit
PieCtrlRegs.PIEACK.all = PIEACK_GROUP1; // Acknowledge interrupt to PIE

return;
}

sir please help me where am i wrong?
if any modification is necessary in this code.

0 Elizabeth Joy over 8 years ago in reply to Jitendra nama

TI__Expert 5940 points

To assist those reading this post in the future, this discussion is continued at:
e2e.ti.com/.../2040875

Elizabeth

C2000™︎ microcontrollers

C2000 microcontrollers forum

F28335 EPWM to GPIO