AM625: EPWM configuration

Hello Koichiro-san,

I assume the customer is controlling the EPWM from A53 cores running Linux?

Please refer to the Linux SDK docs
https://software-dl.ti.com/processor-sdk-linux/esd/AM62X/09_01_00_08/exports/docs/linux/Foundational_Components/Kernel/Kernel_Drivers/PWM.html

They can achieve that with the period and duty cycle settings.

Regards,

Nick

Hi Nick,

Thanks for your reply, but the customer wants to know exact registers configuration, not Linux driver usage.
He wants to control EPWM0 duty between 0 to 100% for LCD backlight control.
He understood registers in TRM Table 12-310 need to be configured properly, but he could not find programming model or example in TRM.

Thanks and regards,
Koichiro Tashiro

Hello Koichiro,

We can support specific questions about TI hardware or TI software on the forums, but we cannot support custom driver development. The customer is welcome to reference the logic in the Linux driver at pwm/pwm-tiehrpwm.c if they are looking for a reference.

If they have a specific question about a specific register, then I can reassign the thread to the hardware team member to comment.

Regards,

Nick

Hi Nick,

I see. The customer has below questions. TRM does not provide these information.
Q1) EPWM_TBCTRL register, CTRMODE bitfield.
What does 00, 01, 10, 11 mean ?
Q2) EPWM_AQCTRLA register, CBD, CBU, CAD, CAU, PRD, ZRO bitfields.
Please provide actions for each settings (00, 01, 10, 11).

Thanks and regards,
Koichiro Tashiro

Hello Koichiro-san,

I am reassigning your thread to a HW team member. Feel free to ping the thread if you do not get a response within several business days.

Regards,

Nick

Hello Koichiro Tashiro,

Let me check with the TRM expert.

Please check if the below document helps 

https://www.ti.com/lit/an/spraai1/spraai1.pd

https://www.ti.com/lit/ug/sprufz6b/sprufz6b.pdf

Regards,

Sreenivasa

Hi Sreenivasa,

Documents you listed are for C2000 device. Are you sure EPWM Register sets are the same as AM62x?

Thanks and regards,
Koichiro Tashiro

Hello Koichiro Tashiro,

Thank you for the note.

The referenced document should help clarify your query.

I guess the IP is similar but i am checking internally.

Regards,

Sreenivasa

Hi Sreenivasa,

I see. Thanks!
Please take an action to update AM62x TRM will properly include register descriptions.

Thanks and regards,
Koichiro Tashiro

Hello Koichiro Tashiro,

Thank you.

As i understand the root cause is the information missing in the source file that is being look into.

I have a JOIRS submitted that the documentation team would follow-up.

I do not have a timeline when the TRM (s) would be updated.

Regards,

Sreenivasa