topic Re: PWM using CTimer in Wi-Fi® + Bluetooth® + 802.15.4

PWM using CTimer

hrm2519 — Fri, 15 Mar 2024 08:54:47 GMT

I am trying to generate PWM using CTimer but there isn't any sample code provided by NXP. I am using RW6xx series MCU. Could you help me with this?

Re: PWM using CTimer

nxf77486 — Fri, 15 Mar 2024 22:09:21 GMT

Hello,

Thank you in advance for contacting NXP support.

As this product has not been yet released t mass market the only information we have available is the one you can find in the product page or SDK release.

By any chance do you already have a board with you of the RW6xx?

Re: PWM using CTimer

hrm2519 — Mon, 18 Mar 2024 06:06:43 GMT

Thank you for the response.

Yes, I do have the RW6xx EVKit with me.

Let me explain the scenario:

1. I flashed the zephyr blinky_pwm sample to the nRF5340 development kit. It works as expected since the logic analyzer output shows frequency being doubled after every 4 seconds.

2. I tried the same sample on NXP RW6xx EVKit. I added an overlay file where I used the SCTimer to generate the PWM. I used channel 9. But this output isn't the same as the Nordic board. After digging into the driver code, I got to know that the driver itself is designed such that it will generate 2 events for every frequency change. Since there are a total of 16 events, this causes the driver to throw an error since the events get used after frequency is changed 8 times. There is a fix in the zephyr repo https://github.com/zephyrproject-rtos/zephyr/pull/66301 but I am not sure why this wasn't included in the NXP release. If I modify the sctimer driver code as per the Zephyr PR, then the behavior is identical to the Nordic board. Due to the above issue, I thought of trying CTimer to generate the PWM.

Any guidance as per the above scenario would be helpful.

Re: PWM using CTimer

nxf77486 — Tue, 19 Mar 2024 20:11:08 GMT

Hello,

I just send you a private message, can you please help me checking this.