PWM via EasyDMA

RE: PWM via EasyDMA

Priyanka — Tue, 04 Nov 2025 13:03:23 GMT

I don't think there is any "direct" register for this, but maybe you can check the following registers:

They tell you the number of bytes after a sequence completion and how many bytes from your RAM buffer have been read so far during the ongoing sequence respectively.

You can also track the following registers:

-Priyanka

RE: PWM via EasyDMA

Rm3 — Tue, 04 Nov 2025 11:06:22 GMT

Thank you Priyanka, that is very helpful.

Is it possible to query the current duty cycle somehow/know how far into pwm_seq the pwm has got?

Many thanks.

RE: PWM via EasyDMA

Priyanka — Tue, 04 Nov 2025 09:42:30 GMT

Hi,

Please take a look at the code snippets mentioned in this documentation:

https://docs.nordicsemi.com/bundle/ps_nrf54L15/page/pwm.html#ariaid-title2

From the code snippets,

pwm_seq is an array in RAM holding the duty cycle values for each channel.
The .PTR register points to this array, and .MAXCNT sets the number of values to transfer.
The DECODER register is set to load individual values for each channel.
The TASKS_DMA.SEQ[0].START task triggers EasyDMA to start transferring the values from RAM to the PWM peripheral, updating the duty cycle accordingly.

-Priyanka