Low pass filter for ADMP421 MEMS digital microphone

Wish to use a decimating filter in a microcontroller to interface a MEMS microphone (ADMP421). Has anyone used a microcontroller to do this?The sampling frequency is 1MHz (the minimum requirement for the MEMS mic).

We eventually want to recover a base band (audio) data with a maximum frequency of just 5 to 8KHz. We intend clocking in all of the data from the MEMS digital output and passing it though a lowpass filter before decimation. The design of this low pass and decimation filter at that clocking frequency of a serial dalte-sigma modulator is what we are after.

Any guidance will be appreciated.

Thanks,

Anand C J