> ## Documentation Index
> Fetch the complete documentation index at: https://dragonwingdocs.qualcomm.com/llms.txt
> Use this file to discover all available pages before exploring further.

# UART 

| **Subsystem** | **Transfer mode**                              | **Description**                                                                                                                                                                                                                                                                                                                                                                                                                                      |
| ------------- | ---------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| RTSS          | <ul><li>FIFO (low sleep)</li><li>DMA</li></ul> | <ul><li>Supports 9600, 115200, 230400, and 921600 baud rates.</li><li>The FIFO mode transfers data between its Rx/Tx buffers and system memory.</li><li>The DMA mode transfers data between its Rx/Tx buffers and system memory. Enhanced performance is achieved through high-speed UART drivers that support higher baud rates and larger data packets. For example, the Bluetooth<sup>®</sup> wireless technology connectivity modules.</li></ul> |

## **UART interface components**

The devicetree source is at `sail_proc/BSP/scripts/lemansau-sailhyp.dts`.

## **UART APIs**

The UART APIs for the RTSS are listed at `sail_proc/BSP/uart/public/uart.h`.

## **UART software devicetree configuration**

To enable UART, configure UART using the devicetree node. The following is an example of devicetree node:

```powershell theme={null}
se2_uart: qupv3_se2_uart {
                     reg-base = <0xF1908000>;
                     clock-name = <clock_name>;
                     clock-frequency = <7372800>;
                     baudrate = <115200>;
                     interrupt = <404>;
                     pinctrl = <address node of pinctrl>;
                     pinctrl-monaco = <address node of pinctrl>;
                     parity = <4>;
                     stop-bit = <0>;
                     access-mode= <2>;
                     loopback  = <0>;
                     status = <1>;
};
```