ePWM1A pin in TMS320F28335 hardware

Mahesh Venugopal

Intellectual 415 points

Other Parts Discussed in Thread: TMS320F28335

Hi all..

I'm a beginner in TMS320F28335.

How can i access ePWM1A pin in hardware?

In hardware there are around 54 gpio pins,14 adc pins,ground pins,vcc pins are available.

this was the command to activate epwm pin:

GpioCtrlRegs.GPAMUX1.bit.GPIO0 = 1;

Please tell me how should i access this pin..

thanks & regards

Mahesh

over 13 years ago

0 David M. Alter over 13 years ago

TI__Guru 61235 points

Mahesh,

To use the PWM, you need to configure the GPIO pin mux, and then configure the PWM peripheral. You show code to configure the PWM1A pin as PWM. That is correct. Now you need to configure the ePWM1 module so that it actually generates PWM. Appnote SPRA958 has code that can be used as a good starter framework:

http://www.ti.com/mcu/docs/litabsmultiplefilelist.tsp?sectionId=96&tabId=1502&literatureNumber=spra958l&docCategoryId=1&familyId=1414

The code has ePMW1A pin outputting PWM, among other things.

Note that your pin mux config code needs to be bracketed by EALLOW/EDIS:

asm(" EALLOW"); // Enable EALLOW protected register access
GpioCtrlRegs.GPAMUX1.bit.GPIO0 = 1;
asm(" EDIS"); // Disable EALLOW protected register access

Regards,

David

0 Mahesh Venugopal over 13 years ago in reply to David M. Alter

Intellectual 415 points

Hi David

Thanks for your answer.

But my question was how to access that pin in my TMS320F28335 hardware kit?

There are many no. of pins are available.

Some are written GPIO's.Which are epwm pins?

regards

Mahesh

0 David M. Alter over 13 years ago in reply to Mahesh Venugopal

TI__Guru 61235 points

Mahesh,

The pin muxing is documented in the device datasheet. I'm not seeing what you're asking. ePWM1A signal will appear on GPIO0 for example, when the GPIO0 pin mux is configured as such. How to access GPIO0 on your hardware kit depends on the hardware kit. You'd need to look at the schematic is see where GPIO0 is run out. Usually there are pin headers on the boards. I don't know what board you are using.

- David

0 Gautam Iyer over 13 years ago in reply to Mahesh Venugopal

Guru 192875 points

Hi Mahesh,

To be precise, in TMS320F28335:

GPIO00 -> GPIO0/EPWM1A

GPIO01 -> GPIO1/EPWM1B etc......

So using the following statement you can select whether to configure the pin as a GPIO or as a ePWM generator:

GpioCtrlRegs.GPAMUX1.bit.GPIO0 = 1; // 0=GPIO, 1=EPWM1A, 2=Resv, 3=Resv

I hope your question is answered.

Regards,

Gautam

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ePWM1A pin in TMS320F28335 hardware