1The USART Synchronous Driver
2============================
3
4The universal synchronous and asynchronous receiver and transmitter
5(USART) is usually used to transfer data from one device to the other.
6
7User can set action for flow control pins by function usart_set_flow_control,
8if the flow control is enabled. All the available states are defined in union
9usart_flow_control_state.
10
11Note that user can set state of flow control pins only if automatic support of
12the flow control is not supported by the hardware.
13
14Features
15--------
16
17* Initialization/de-initialization
18* Enabling/disabling
19* Control of the following settings:
20
21  * Baudrate
22  * UART or USRT communication mode
23  * Character size
24  * Data order
25  * Flow control
26* Data transfer: transmission, reception
27
28Applications
29------------
30
31They are commonly used in a terminal application or low-speed communication
32between devices.
33
34Dependencies
35------------
36
37USART capable hardware.
38
39Concurrency
40-----------
41
42Write buffer should not be changed while data is being sent.
43
44
45Limitations
46-----------
47
48* The driver does not support 9-bit character size.
49* The "USART with ISO7816" mode can be only used in ISO7816 capable devices.
50And the SCK pin can't be set directly. Application can use a GCLK output PIN
51to generate SCK. For example to communicate with a SMARTCARD with ISO7816
52(F = 372 ; D = 1), and baudrate=9600, the SCK pin output frequency should be
53config as 372*9600=3571200Hz. More information can be refer to ISO7816 Specification.
54
55Known issues and workarounds
56----------------------------
57
58N/A
59