| Bits | Description |
|---|---|
| 7:6 | Reserved, must be 0 |
| 5 | Enable UART on GPIO 14,15 (overrides gpio)* (soft reset = 0) |
| 4 | 0 to connect Rx to GPIO 15, Tx to GPIO 14 (for comm with pi hats) (soft reset = 0) = 1 to connect Rx to GPIO 14, Tx to GPIO 15 (for comm with pi) |
| 3 | Enable I2C on GPIO 2,3 (override gpio) (soft reset = 0) |
| 2:1 | Reserved, must be 0 |
| 0 | Enable SPI on GPIO 7,8,9,10,11 (overrides gpio) (soft reset = 0) |
* GPIO 16,17 will function as rtr_n and cts_n if the uart is in hw flow control mode