TMS320F28377S: How to Map An External Sync Signal into EPwm1

Andrew Barnett

I am using a TMS320F28377S and need to map an external PWM sync signal into EPwm1, with downstream PWMs sync'd to EPwm1.

EPwm1 is set to up-down count.

I have set the following registers / bits:

InputXbarRegs.INPUT5SELECT = 78; /* This maps GPIO78 to InputXBAR5. GPIO78 is configured as an input. */

EPwm1Regs.TBCTL.bit.PHSEN = TB_ENABLE; /* Enable counter load from TBPHS whne EPWM1SYNCI occurs. TBPHS SET TO 0 */

EPwm1Regs.TBCTL.bit.SYNCOSEL = TB_SYNC_IN; SYNCOUT = EPWM1SYNCI */

Given these settings, I do not appear to be able to sync to the external signal.

Are there any other registers or bits I need to set to ensure that InputXBAR5 is mapped to EXTSYNCIN1?

Thanks in advance for any insight.

over 6 years ago

0 Vasudha Bhadoria over 6 years ago

TI__Genius 10845 points

Hi,

Is the GPIO78 being configured as input in the example? You might require the pull up and qualification related configurations for the selected GPIO.

Thanks

Vasudha

0 Vasudha Bhadoria over 6 years ago

TI__Genius 10845 points

Hi,

andrew barnett71 said:
InputXbarRegs.INPUT5SELECT = 78; /* This maps GPIO78 to InputXBAR5. GPIO78 is configured as an input. */

Also, the above line of code is EALLOW protected. PFB a sample configuration for input XBAR

//
// For External Trigger, GPIO12 as the trigger for TripZone
//
GpioCtrlRegs.GPAPUD.bit.GPIO12 = 0; // Enable pull-up on GPIO12 (TZ1)

GpioCtrlRegs.GPAQSEL1.bit.GPIO12 = 3; // Asynch input GPIO12 (TZ1)

EALLOW;
InputXbarRegs.INPUT1SELECT = 12;
EDIS;

Thanks

Vasudha

0 Andrew Barnett over 6 years ago in reply to Vasudha Bhadoria

Intellectual 870 points

it's not shown in my code snippet, but EALLOW and EDIS are set before I set InputXbarRegs.INPUT5SELECT

0 Vasudha Bhadoria over 6 years ago in reply to Andrew Barnett

TI__Genius 10845 points

Hi,

Were you able to resolve this issue? Is the GPIO configured as input correctly?

Thanks

Vasudha

0 Andrew Barnett over 6 years ago in reply to Vasudha Bhadoria

Intellectual 870 points

yes, thank you

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TMS320F28377S: How to Map An External Sync Signal into EPwm1