ST STM32F446 Series - USART Main Features

RM0390 Rev 4 795/1328
RM0390 Universal synchronous asynchronous receiver transmitter (USART)
845
25.2 USART main features
• Full duplex, asynchronous communications
• NRZ standard format (Mark/Space)
• Configurable oversampling method by 16 or by 8 to give flexibility between speed and
clock tolerance
• Fractional baud rate generator systems
– Common programmable transmit and receive baud rate (refer to the datasheets
for the value of the baud rate at the maximum APB frequency.
• Programmable data word length (8 or 9 bits)
• Configurable stop bits - support for 1 or 2 stop bits
• LIN Master Synchronous Break send capability and LIN slave break detection
capability
– 13-bit break generation and 10/11 bit break detection when USART is hardware
configured for LIN
• Transmitter clock output for synchronous transmission
• IrDA SIR encoder decoder
– Support for 3/16 bit duration for normal mode
• Smartcard emulation capability
– The Smartcard interface supports the asynchronous protocol Smartcards as
defined in the ISO 7816-3 standards
– 0.5, 1.5 stop bits for Smartcard operation
• Single-wire half-duplex communication
• Configurable multibuffer communication using DMA (direct memory access)
– Buffering of received/transmitted bytes in reserved SRAM using centralized DMA
• Separate enable bits for transmitter and receiver
• Transfer detection flags:
– Receive buffer full
– Transmit buffer empty
– End of transmission flags
• Parity control:
– Transmits parity bit
– Checks parity of received data byte
• Four error detection flags:
– Overrun error
– Noise detection
– Frame error
– Parity error
• Ten interrupt sources with flags:
– CTS changes
– LIN break detection
– Transmit data register empty
– Transmission complete