PDM control register
| PDMEN | PDM enable |
| MICNBR | Number of microphones |
| CKEN1 | Clock enable of bitstream clock number 1 |
| CKEN2 | Clock enable of bitstream clock number 2 |
| CKEN3 | Clock enable of bitstream clock number 3 |
| CKEN4 | Clock enable of bitstream clock number 4 |