CCS/RM46L852: Synchronize EPWM with external signal

Martin Valencia

Part Number: RM46L852
Other Parts Discussed in Thread: HALCOGEN

Tool/software: Code Composer Studio

Good morning,

I want to synchronize a 600Hz pwm, with an external 60Hz signal, coming from the electrical network.

So I configured the etpwm module to generate a 600Hz output and enable Het1_16, as a synchronization input (EPWM1SYNCI), but I can't get the signals to synchronize

I attach images:

1.- Configure the multiplexing of pins

Here is something to be modified?

Signals not syncing

Code:

void TreePhaseInit() {
etpwmDeadBandConfig_t Set_DBand; // declaracion de variable
/*Configuracion de la banda muerta*/
Set_DBand.halfCycleEnable = false;
Set_DBand.inputmode = PWMA_RED_PWMB_FED;
Set_DBand.outputmode = PWMB_FED_PWMA_RED;
Set_DBand.polarity = Invert_PWMB;

etpwmInit();
/*Configuracion del angulo de desfase entre los PWM generados*/
etpwmSetSyncOut(etpwmREG1, SyncOut_EPWMxSYNCI);

etpwmDisableCounterLoadOnSync(etpwmREG1);

/* Set the time period as 1000 ns (Divider value = (1000ns * 2MHz) - 1 = 89)*/
etpwmSetTimebasePeriod(etpwmREG1, 3333U);

/* Configure Compare to register 1 */
etpwmSetCmpA(etpwmREG1, 3333 / 2);
etpwmSetCmpB(etpwmREG1, 3333 / 2);
/*Iniciando el control del modulo chopping de pwm*/
/*Iniciando la carga de los valor de la banda muerta 1000---> 510 microsegundos*/
etpwmSetDeadBandDelay(etpwmREG1, 1000, 1000);
etpwmEnableDeadBand(etpwmREG1, Set_DBand);

}

Attached complete program code:

2134.RM46_ETPWM_TRIFASICO_2017.rar

Please, I await your comments, maybe some configuration is missing!

over 5 years ago

0 Sunil Oak over 5 years ago

TI__Mastermind 49120 points

Martin,

ePWMSYNCI is an input function, so you don't need to switch the multiplexor to select the ePWMSYNCI. Let N2HET_16 function be output on the assigned terminal, and it is automatically "seen" by the ePWM1 as the SYNCI input.

0 Martin Valencia over 5 years ago in reply to Sunil Oak

Guru 15185 points

Modify the multiplexing of the Pin, but it still does not synchronize!

0 Sunil Oak over 5 years ago in reply to Martin Valencia

TI__Mastermind 49120 points

Martin,

The SYNCI input to ePWM1 is used to load the time-base counter with the value in the TBPHS register. You can load TBPHS with a value very close to the compare value that sets the ePWM1 pin High to see that it is working correctly.

You also need to enable this load by setting the PHSEN bit of the TBCTL register. The default operation is to ignore the SYNCI input.

0 Jan Cumps over 5 years ago

Guru 15740 points

We tested it, and this combination in HALCoGen makes it work:

EPWM1SYNCI can be ASYNC or SYNC. It works in both combinations. But Time Based Sync needs to be off, TBCLK sync on.

0 Sunil Oak over 5 years ago in reply to Jan Cumps

TI__Mastermind 49120 points

Thanks Jan. Yes, the TBCLKSYNC is gated off by default. This controls the time-base clock for all ePWM modules. This does need to be enabled using the "Enable TBCLK Sync" switch in HALCoGen to enable this time-base clock for all ePWM modules.

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CCS/RM46L852: Synchronize EPWM with external signal