Universal synchronous/asynchronous receiver transmitter (USART/UART) RM0440
1594/2126 RM0440 Rev 4
37.2 USART main features
• Full-duplex asynchronous communication
• NRZ standard format (mark/space)
• Configurable oversampling method by 16 or 8 to achieve the best compromise
between speed and clock tolerance
• Baud rate generator systems
• Two internal FIFOs for transmit and receive data
Each FIFO can be enabled/disabled by software and come with a status flag.
• A common programmable transmit and receive baud rate
• Dual clock domain with dedicated kernel clock for peripherals independent from PCLK
• Auto baud rate detection
• Programmable data word length (7, 8 or 9 bits)
• Programmable data order with MSB-first or LSB-first shifting
• Configurable stop bits (1 or 2 stop bits)
• Synchronous master/slave mode and clock output/input for synchronous
communications
• SPI slave transmission underrun error flag
• Single-wire Half-duplex communications
• Continuous communications using DMA
• Received/transmitted bytes are buffered in reserved SRAM using centralized DMA.
• Separate enable bits for transmitter and receiver
• Separate signal polarity control for transmission and reception
• Swappable Tx/Rx pin configuration
• Hardware flow control for modem and RS-485 transceiver
• Communication control/error detection flags
• Parity control:
– Transmits parity bit
– Checks parity of received data byte
• Interrupt sources with flags
• Multiprocessor communications: wakeup from Mute mode by idle line detection or
address mark detection