F28069 sinusoidal PWM generation

Hi Naveenkumar,

Naveenkumar Marati said:

Does any body know how to create Sinusoidal PWM for with 50Hz referennce and 10khz carrier waveform, using F28069 experimental kit , please help in this regard

Have you already gone through the SGEN library?

C:\ti\controlSUITE\libs\dsp\SGEN\v101

You can read the doc present here: C:\ti\controlSUITE\libs\dsp\SGEN\v101\doc

Regards,

Gautam

Naveenkumar Marati said:

I have read  but I have to generate a Sinusoidal PWM pulse with 50Hz ref and 10khz carrier signal.

Ahhh... this link should be helpful then:

http://e2e.ti.com/support/microcontrollers/c2000/f/171/t/253748.aspx

Regards,

Gautam

Oh I confused Gautam,

Actually I took some examples and I have modified for SPWM here I am providing the code 

#include "F2806x_Device.h"
#include "IQmathLib.h"
#pragma DATA_SECTION(sine_table,"IQmathTables");
_iq30 sine_table[512];

// external function prototypes
extern void InitSysCtrl(void);
extern void InitPieVectTable(void);
extern void InitPieCtrl(void);

// Prototype statements for functions found within this file.
void Gpio_Select(void);
void Setup_ePWM1(void);
interrupt void ePWM1_compare_isr(void);

//###########################################################################
// main code
//###########################################################################
void main(void)
{
InitSysCtrl(); // Basic Core Init from DSP2806x_SysCtrl.c

EALLOW;
SysCtrlRegs.WDCR= 0x00AF; // Re-enable the watchdog
EDIS; // 0x00AF to NOT disable the Watchdog, Prescaler = 64

DINT; // Disable all interrupts

Gpio_Select(); // GPIO34 as output (LED) & EPWM1A

Setup_ePWM1(); // init of ePWM1A

InitPieCtrl(); // basic setup of PIE table; from DSP2833x_PieCtrl.c

InitPieVectTable(); // default ISR's in PIE

EALLOW;
PieVectTable.EPWM1_INT = &ePWM1_compare_isr;
EDIS;

PieCtrlRegs.PIEIER3.bit.INTx1 = 1; // ePWM1 Interrupt

IER |=1;

EINT;
ERTM;

while(1)
{
EALLOW;
SysCtrlRegs.WDKEY = 0x55; // service WD #1
EDIS;
}
}

void Gpio_Select(void)
{
EALLOW;
GpioCtrlRegs.GPAMUX1.all = 0; // GPIO15 ... GPIO0 = General Puropse I/O
GpioCtrlRegs.GPAMUX1.bit.GPIO0 = 1; // ePWM1A active
GpioCtrlRegs.GPAMUX1.bit.GPIO1 = 1; // ePWM1B active
GpioCtrlRegs.GPAMUX2.all = 0; // GPIO31 ... GPIO16 = General Purpose I/O
GpioCtrlRegs.GPBMUX1.all = 0; // GPIO38 ... GPIO32 = General Purpose I/O
GpioCtrlRegs.GPADIR.all = 0;
GpioCtrlRegs.GPBDIR.all = 0; // GPIO38-32 as inputs
GpioCtrlRegs.GPBDIR.bit.GPIO34 = 1; // GPIO34 as output (LED LD2 at 28027stick)
EDIS;
}

void Setup_ePWM1(void)
{
EPwm1Regs.TBCTL.all = 0; // default status
EPwm1Regs.TBCTL.bit.CLKDIV = 0; // CLKDIV = 1
EPwm1Regs.TBCTL.bit.HSPCLKDIV = 0; // HSPCLKDIV = 1
EPwm1Regs.TBCTL.bit.CTRMODE = 2; // up - down mode

EPwm1Regs.AQCTLA.all = 0x0060; // set ePWM1A on CMPA up
EPwm1Regs.AQCTLB.all = 0x0090; // clear ePWM1A on CMPA down

EPwm1Regs.TBPRD = 90; // 500KHz - PWM signal
// TBPRD = fcpu / (2*fPWM * CLKDIV * HSPCLKDIV)
// TPPRD = 60 MHz / (2 * 1KHz * 1 * 1) = 60
EPwm1Regs.CMPA.half.CMPA = EPwm1Regs.TBPRD / 2; // 50% duty cycle first
EPwm1Regs.CMPB = EPwm1Regs.TBPRD / 2;

EPwm1Regs.DBRED = 200; // 10 microseconds delay
EPwm1Regs.DBFED = 200; // for rising and falling edge
EPwm1Regs.DBCTL.bit.OUT_MODE = 3; // ePWM1A = RED
EPwm1Regs.DBCTL.bit.POLSEL = 2; // S3=1 inverted signal at ePWM1B
EPwm1Regs.DBCTL.bit.IN_MODE = 0; // ePWM1A = source for RED & FED

EPwm1Regs.ETSEL.all = 0;
EPwm1Regs.ETSEL.bit.INTEN = 1; // interrupt enable for ePWM1
EPwm1Regs.ETSEL.bit.INTSEL = 5; // interrupt on CMPA down match
EPwm1Regs.ETPS.bit.INTPRD = 1; // interrupt on first event
}

interrupt void ePWM1_compare_isr(void)
// ISR runs every 2000 ns (PWM-frequency = 500 KHz)
// and is triggered by ePWM1 compare event
// run - time of ISR is 630 ns
{
static unsigned int up_down=1;
// Service watchdog every interrupt
EALLOW;
SysCtrlRegs.WDKEY = 0xAA; // Service watchdog #2
EDIS;
if(up_down)
{
if(EPwm1Regs.CMPA.half.CMPA < EPwm1Regs.TBPRD)
EPwm1Regs.CMPA.half.CMPA = EPwm1Regs.TBPRD - _IQsat(_IQ30mpy((sine_table[up_down]+_IQ30(0.9999))/2,EPwm1Regs.TBPRD),EPwm1Regs.TBPRD,0);
up_down +=1; // use next element out of lookup table
if(up_down >511) up_down = 0;

}
else
{

if(EPwm1Regs.CMPA.half.CMPA > 0)
EPwm1Regs.CMPA.half.CMPA = EPwm1Regs.TBPRD - _IQsat(_IQ30mpy((sine_table[up_down]+_IQ30(0.9999))/2,EPwm1Regs.TBPRD),EPwm1Regs.TBPRD,180);

up_down --; // use next element out of lookup table
if (up_down >511) up_down = 1;
}
PieCtrlRegs.PIEACK.all = PIEACK_GROUP1;

EPwm1Regs.ETCLR.bit.INT = 1; // Clear ePWM1 Interrupt flag

// Acknowledge this interrupt to receive more interrupts from group 3
PieCtrlRegs.PIEACK.all = 1;
}
//===========================================================================
// End of SourceCode.
//===========================================================================

But this for 500kHz and 976Hz whenI applied to Haif bridge inverter I am not getting proper output at LC filter please could you help me in this  

Naveenkumar Marati said:

But this for 500kHz and 976Hz whenI applied to Haif bridge inverter I am not getting proper output at LC filter please could you help me in this  

Do the calculations and edit the TBPRD value; as simple as that!

Regards,

Gautam

I have calculated the value and TBPRD is 2250 for 10khz but when I gate puelse to Inverter the output volatge has to vary with input but it is not varying accordingly.