Global mode channel.
| LSB_FIRST | LSB Transmit Receive First. |
| CH_MODE | SCK Select. |
| WS_POL | WS polarity select. |
| MSB_LOC | MSB location. |
| ALIGN | Align to MSB or LSB. |
| EXT_SEL | External SCK/WS selection. |
| STEREO | Stereo mode of I2S. |
| WSIZE | Data size when write to FIFO. |
| TX_EN | TX channel enable. |
| RX_EN | RX channel enable. |
| FLUSH | Flushes the TX/RX FIFO buffer. |
| RST | Write 1 to reset channel. |
| FIFO_LSB | Bit Field Control. |
| RX_THD_VAL | depth of receive FIFO for threshold interrupt generation. |