TWR-KV46F150M : SDK Example : PWM Driver : No output Pulse on Submodule1(SM1)

[EmbedALM]

Hello,

I am working with the TWR-KV46F150M evaluation board and using MCUXpresso IDE. I have downloaded and installed SDK version 2.8.0 for the TWR-KV46F150M. I am currently testing the PWM driver example by directly importing it from the SDK. i have attached the screen shot of the  example project i have imported from SDK.

Steps Taken:

1. Imported the PWM driver example from the SDK.
2. Compiled the project and uploaded it to the board successfully without any errors.
3. Observed the PWM output on the assigned pins.

Issue:

I can see the PWM output on the pin corresponding to submodule 0, but there is no PWM output on the pin assigned to submodule 1.

Observations:

• I confirmed that the example code is unmodified, and the project settings are default as provided in the SDK.
• I verified the pin assignments and checked the schematics to ensure proper connections.
• Submodule 0 is working as expected, but submodule 1 does not generate any signal on the corresponding pin.

Questions:

1. Is there an additional configuration required in the example to enable PWM output on submodule 1?
2. Could this issue be related to the board's hardware configuration, or is it likely a software setup issue?
3. Are there any known issues with the SDK version 2.8.0 for this board regarding PWM submodules?

Additional Information:

• Board: TWR-KV46F150M
• IDE: MCUXpresso IDE
• SDK Version: 2.8.0
• Example: PWM driver example (directly imported without modifications)

Thank you for your assistance. Any guidance or suggestions to resolve this issue will be greatly appreciated.

[Alice_Yang]

Hello @EmbedALM 

When running the demo, what message is displayed in the terminal?

And please refer to readme.txt to measure the signal using an oscilloscope.

* Probe the pwm signal using an oscilloscope
- At J501_9
- At J501_11
- At J501_30
- At J501_34

BR

Alice

[EmbedALM]

Hello Alice,

Thank you for your response. I checked the terminal, and it displays only "FlexPWM driver example". I also followed the instructions in the readme.txt and probed the pins using an oscilloscope as suggested.

Here’s what I observed:

• The PWM signal is present at the pins corresponding to submodule 0.
• No signal is observed at the pins assigned to submodule 1.

Additionally, I tried modifying the code by changing the clock setting for submodule 1. Specifically, I replaced:

"pwmConfig.clockSource = kPWM_Submodule0Clock;"

with 

"pwmConfig.clockSource = kPWM_BusClock;"

After making this change, I observed that a pulse was generated on the submodule 1 pin as well.

Could you clarify:

1. Why submodule 1 does not output a signal when kPWM_Submodule0Clock is used as the clock source?

[Alice_Yang]

Hello @EmbedALM 

I have tested the PWM demo on my side, and I have the same issue as yours. Finally, I checked a thread to analyze this issue.

https://community.nxp.com/t5/Kinetis-Support/SDK-PWM-demo-error-on-some-PWM-pins/ta-p/1310710 

"

Diagnosis

The root cause of the issue is that the demo configures the prescale divider for submodules 1 and 2 to a divide of two.  In addition, these submodules use the Master Sync from submodule 0 for the initialization control.  This, coupled with a clock that is twice as slow as submodule 0, causes submodules 1 and 2 to re-initialize before the output pins are able to change states.  

Solution

Set the prescale divide for submodules 1 and 2 to a divide of one (instead of two). 

"

I hope this information helps you. 

BR

Alice