ST STM32F31xx User Manual

Universal synchronous asynchronous receiver
transmitter (USART)
UM1581
540/584
DocID023800 Rev 1
After configuring the source of WakeUp and before entering in Stop Mode
USART_STOPModeCmd() function should be called to allow USART WakeUp.
 USART_STOPModeCmd()
 USART_StopModeWakeUpSourceConfig()
23.2.7 AutoBaudRate functions
This subsection provides a set of functions allowing to manage the AutoBaudRate
detections.
Before Enabling AutoBaudRate detection using USART_AutoBaudRateCmd () The
character patterns used to calculate baudrate must be chosen by calling
USART_AutoBaudRateConfig() function. These function take as parameter :
1. USART_AutoBaudRate_StartBit : any character starting with a bit 1.
2. USART_AutoBaudRate_FallingEdge : any character starting with a 10xx bit pattern.
At any later time, another request for AutoBaudRate detection can be performed using
USART_RequestCmd() function.
The AutoBaudRate detection is monitored by the status of ABRF flag which indicate that
the AutoBaudRate detection is completed. In addition to ABRF flag, the ABRE flag indicate
that this procedure is completed without success. USART_GetFlagStatus () function should
be used to monitor the status of these flags.
 USART_AutoBaudRateCmd()
 USART_AutoBaudRateConfig()
23.2.8 Data transfers functions
This subsection provides a set of functions allowing to manage the USART data transfers.
During an USART reception, data shifts in least significant bit first through the RX pin.
When a transmission is taking place, a write instruction to the USART_TDR register stores
the data in the shift register.
The read access of the USART_RDR register can be done using the
USART_ReceiveData() function and returns the RDR value. Whereas a write access to the
USART_TDR can be done using USART_SendData() function and stores the written data
into TDR.
 USART_SendData()
 USART_ReceiveData()
23.2.9 Multi-Processor Communication functions
This subsection provides a set of functions allowing to manage the USART multiprocessor
communication.
For instance one of the USARTs can be the master, its TX output is connected to the RX
input of the other USART. The others are slaves, their respective TX outputs are logically
ANDed together and connected to the RX input of the master. USART multiprocessor
communication is possible through the following procedure:

ST STM32F31xx Specifications

General

Brand	ST
Model	STM32F31xx
Category	Microcontrollers
Language	English