We used an ADAU1761 to create a simple microphone beamforming application, with two omnidirectional ADMP504 MEMS microphones mounted in an endfire configuration.
Using the attached Excel sheet to perform the calculations, we calculated that a total of 6 samples of delay are required to generate a delay appropriate for a microphone spacing of 42 mm at a sample rate of 48 kHz.
The following project was created to realize the signal flow.
Microphone Beamforming Application Note
ADMP504 MEMS Microphone Datasheet