topic Re: MPC5775K FlexPWM ETimer in MPC5xxx

MPC5775K FlexPWM ETimer

ronliu — Thu, 14 Apr 2016 09:08:19 GMT

Hi,

How could I generate PWM in the FlexPWM module? Is there some sample code to share?

Besides, I'd like to capture the frequency of PWM. Is it available to make it in the ETimer_ETC module?

Regards,

Ron

Re: MPC5775K FlexPWM ETimer

petervlna — Thu, 14 Apr 2016 09:50:47 GMT

Hi,

Always check community before asking a question.

1. Here is example for FlexPWM (It is for different processor, but the module is the same)

Example MPC5604P FlexPWM Initialization on TRK board

2. Yes you can capture the PWM signal with FlexPWM or with eTimer.

Peter

Re: MPC5775K FlexPWM ETimer

ronliu — Wed, 20 Apr 2016 03:38:44 GMT

Hi Peter,

Maybe it is necessary to describe all the details. I want to generate a configurable duty PWM in the FlexPWM module. And the output pin is X0. But I couldn't get the PWM . The below is my code sample. I don't know why it was not able to work. Could you correct it for me?

Thanks.

The MCU which I am working with is MPC 5775K.

The pin is GPIO[57], FlexPWM0 X0.

void RadarPWMInit(void)
{
      //GPIO[57]
      //PWM0 X0
      SIUL2.MSCR[57].R = 0x02800001;

/* Submodule 0 Initialisation */
FlexPWM_0.OUTEN.B.PWMX_EN = 0x0001; // enable X outputs on submodule 0

      FlexPWM_0.SUB[0].CTRL1.R    = 0x0400; // full cycle reload, every opportunity,IPBus/1
      FlexPWM_0.SUB[0].CTRL2.R    = 0x2000; // independent pair operation
      FlexPWM_0.SUB[0].DTCNT0.R   = 0x0000; // deadtime values, not aplicable on INDEP mode
      FlexPWM_0.SUB[0].DTCNT1.R   = 0x0000; // deadtime
      FlexPWM_0.SUB[0].INIT.R    = 0x0; // PWM init value
      FlexPWM_0.SUB[0].VAL0.R = 4096; // X
      FlexPWM_0.SUB[0].VAL1.R = 1024; // X
      FlexPWM_0.SUB[0].VAL2.R = 0;
      FlexPWM_0.SUB[0].VAL3.R = 0;
      FlexPWM_0.SUB[0].VAL4.R = 0;
      FlexPWM_0.SUB[0].VAL5.R = 0;
      FlexPWM_0.SUB[0].DISMAP.R = 0x0000;

// FlexPWM_0.SUB[0].DMAEN.R = 0x0200; // DMA write requests for VALx registers enabled
// FlexPWM_0.MCTRL.B.LDOK = 0x1; /* Load the PRSC bits of CTRL1 and the INIT, and VALx registers into a set of buffers */

FlexPWM_0.MCTRL.B.RUN = 0x1;
}

Re: MPC5775K FlexPWM ETimer

ronliu — Wed, 20 Apr 2016 08:34:59 GMT

Hi, enwei

I found that the code below was able to work in a single core project. But if I create a new project in a multicore mode. The PWM would never generate the PWM. It was very strange. I don't know how to solve it.

Though there are three cores in the MCU, I only select one core. The FlexPWM module could work in the right way.

void PWMInit(void)
{
uint16_t val_x[4]={0,0,0,0};

SIUL2.MSCR[57].R = 0x02800001; // D[9] pin as FlexPWM X[0] output

//GPIO[57]
//PWM X0
FlexPWM_0.OUTEN.R = 0x001; // enable A,B and X outputs on submodule 0

    FlexPWM_0.SUB[0].CTRL1.R    = 0x0400; // full cycle reload, every opportunity,IPBus/1
    FlexPWM_0.SUB[0].CTRL2.R    = 0x2000; // independent pair operation
    FlexPWM_0.SUB[0].DTCNT0.R   = 0x0000; // deadtime values, not aplicable on INDEP mode
    FlexPWM_0.SUB[0].DTCNT1.R   = 0x0000;
    FlexPWM_0.SUB[0].INIT.R    = 0x0; // PWM init value
    FlexPWM_0.SUB[0].VAL1.R   = 13333; // PWM modulo, PWMX falling edge
    FlexPWM_0.SUB[0].VAL0.R   = 5000;   // PWMX rising edge, half cycle reload point
    FlexPWM_0.SUB[0].VAL2.R   = 0;     // PWM A0 rising edge
    FlexPWM_0.SUB[0].VAL3.R   = 0; // PWM A0 falling edge
    FlexPWM_0.SUB[0].VAL4.R   = 0; // PWM B0 rising edge
    FlexPWM_0.SUB[0].VAL5.R   = 0; // PWM B0 falling edge
    FlexPWM_0.SUB[0].DISMAP.R = 0x0000; // disable fault pin condition

FlexPWM_0.SUB[0].DMAEN.R = 0x0200; // DMA write requests for VALx registers enabled

    /* Load address of source data */
    DMA.TCD[15].SADDR.R = (vuint32_t) &val_x[0];
    /* Read 2 bytes per transfer */
    DMA.TCD[15].ATTR.B.SSIZE = 1;
    /* After transfer, add 2 to src addr */
    DMA.TCD[15].SOFF.B.SOFF = 2;
    /* After major loop, reset src addr */
    DMA.TCD[15].SLAST.B.SLAST = - 8;
    /* Source modulo feature not used */
    DMA.TCD[15].ATTR.B.SMOD = 0;

    /* Load address of destination */
    DMA.TCD[15].DADDR.B.DADDR = (vuint32_t) &FlexPWM_0.SUB[0].VAL2.R;
    /* Write 2 bytes per transfer */
    DMA.TCD[15].ATTR.B.DSIZE = 1;
    /* After transfer, add 2 to dest addr */
    DMA.TCD[15].DOFF.B.DOFF = 2;
    /* After major loop, reset dest addr */
    DMA.TCD[15].DLASTSGA.B.DLASTSGA = - 8;
    /* Destination modulo feature not used */
    DMA.TCD[15].ATTR.B.DMOD = 0;

/* Transfer 8 bytes per minor loop */
DMA.TCD[15].NBYTES.MLNO.B.NBYTES = 8;

    /* Initialize the begining and current major loop iteration counts */
    DMA.TCD[15].BITER.ELINKNO.B.BITER = 1;
    DMA.TCD[15].CITER.ELINKNO.B.CITER = 1;
    DMA.TCD[15].BITER.ELINKNO.B.ELINK = 0;
    DMA.TCD[15].CITER.ELINKNO.B.ELINK = 0;

    DMA.TCD[15].CSR.B.DREQ = 0;
    DMA.TCD[15].CSR.B.INTHALF = 0;
    DMA.TCD[15].CSR.B.INTMAJOR = 0;
    DMA.TCD[15].CSR.B.MAJORELINK = 0;
    DMA.TCD[15].CSR.B.ESG = 0;
    DMA.TCD[15].CSR.B.BWC = 0;
    DMA.TCD[15].CSR.B.START = 0;
    DMA.TCD[15].CSR.B.DONE = 0;
    DMA.TCD[15].CSR.B.ACTIVE = 0;

DMA.ERQ.R = 0x00008000; // eDMA request signal for channel 15 is enabled
DMAMUX_0.CHCFG[15].R |= 0x8a; // route FlexPWM comp_val DMA request to eDMA channel 15

FlexPWM_0.MCTRL.B.RUN = 0x1; // Submodule 0 PWM generator enabled

}

Re: MPC5775K FlexPWM ETimer

petervlna — Wed, 20 Apr 2016 11:16:07 GMT

Hi,

The FlexPWM module is independent of used core.

Your code is missing LDOK bit set for particular module. Without LDOK set the values in FlexPWM registers are still as default. as it is well described in RM.

Please follow the example codes.

Peter

Re: MPC5775K FlexPWM ETimer

ronliu — Thu, 21 Apr 2016 02:39:03 GMT

Thanks. My project seems work now. The PWM module is able to work only when I reset the power.

There may be something more I should do. But I'm not clear at the moment.

I correct the code like this:

// D[9] pin as FlexPWM X[0] output
SIUL2.MSCR[57].R = 0x02800001;

//GPIO[57]
//PWM X0
FlexPWM_0.OUTEN.R = 0x001; // enable A,B and X outputs on submodule 0

    FlexPWM_0.SUB[0].CTRL1.R    = 0x0400; // full cycle reload, every opportunity,IPBus/1
    FlexPWM_0.SUB[0].CTRL2.R    = 0x2000; // independent pair operation
    FlexPWM_0.SUB[0].DTCNT0.R   = 0x0000; // deadtime values, not aplicable on INDEP mode
    FlexPWM_0.SUB[0].DTCNT1.R   = 0x0000;
    FlexPWM_0.SUB[0].INIT.R    = 0x0; // PWM init value
    FlexPWM_0.SUB[0].VAL1.R   = PWM_PERIOD; // PWM modulo, PWMX falling edge
    FlexPWM_0.SUB[0].VAL0.R   = PWM_DUTY;   // PWMX rising edge, half cycle reload point
    FlexPWM_0.SUB[0].VAL2.R   = 0;     // PWM A0 rising edge
    FlexPWM_0.SUB[0].VAL3.R   = 0;   // PWM A0 falling edge
    FlexPWM_0.SUB[0].VAL4.R   = 0;   // PWM B0 rising edge
    FlexPWM_0.SUB[0].VAL5.R   = 0;   // PWM B0 falling edge
    FlexPWM_0.SUB[0].DISMAP.R = 0x0000; // disable fault pin condition
    FlexPWM_0.MCTRL.B.LDOK    = 0x1;

FlexPWM_0.MCTRL.B.RUN = 0x1; // Submodule 0 PWM generator enabled