Clock Configuration Issue for Sound Acquisition with STM32G473VET6 and IMP34DT05TR

[AiROT]

Hello,

I am currently working on a sound acquisition project using the STM32G473VET6 microcontroller and IMP34DT05TR microphone. I am encountering an issue while trying to configure the Serial Audio Interface (SAI) clock frequency. My target frequency is 2.048 MHz, but CubeMX is not allowing me to set this value. Currently, the clock frequency is set at 12 MHz.

I would appreciate any guidance on how to configure the SAI clock to 2.048 MHz or any potential workarounds to achieve this configuration.

Best,

AiROT

[waclawek.jan]

> My target frequency is 2.048 MHz, but CubeMX is not allowing me to set this value

Show.

JW

[AiROT]

Here's the screenshots for the same!

[waclawek.jan]

SAI uses integer divider. You can't divide 24MHz to 2.048MHz. 2MHz should be viable though.

JW

[AiROT]

We are getting error "PLLQ output frequency is currently set to 2Mhz, must be >= 8Mhz and =<150Mhz." Please see the screenshot.

How do we modify this limit?

[waclawek.jan · Accepted solution]

Use the MCKDIV divider in SAI.

JW

[AiROT]

Will try and update you!

[AiROT]

@waclawek.jan thanks, it worked!