STM32 DFSDM, cannot get the right resolution

[NW.2]

Hello STM32-Community,

I'm currently working witha PDM Microphone (SPH0641) and try to get it to work via DFSDM. I'm using the DFSDM tutorial vom STM32 to achieve the resolution required for my system.

Currently I'm using:

Filter Order : 3

Filter Oversampling Ratio: 32

Integrator oversampling ratio 4

with a right bit shift from 6 Bits.

The dma is configured as a contious buffer with a Data Width of a half word for Peripheral and Memory. I want an output-resolution of 12 bit, however the data is always up to 16 Bit. Is there anything wrong in my settings?

Kind regards

NW

[Imen.D]

Hello @NW.2​,

Which STM32 device are you using?

There is a DFSDM example available under STM32CubeL4 MCU Package, at this path: 

\STM32Cube_FW_L4_V1.17.2\Projects\32L476GDISCOVERY\Examples\DFSDM\DFSDM_AudioRecord 

This working DFSDM example will help you to correctly configure your project. 

I advise you to refer to the reference manual of your product to check the resolution and configuration.

Hope this help you.

When your question is answered, please close this topic by choosing Select as Best.

Imen

[GWenJ.1]

/256