Expand description

Request register

Structs

Request register

Register RQR writer

Type Definitions

Field ABRRQ writer - Auto baud rate request Writing 1 to this bit resets the ABRF flag in the USART_ISR and requests an automatic baud rate measurement on the next received data frame. Note: If the USART does not support the auto baud rate feature, this bit is reserved and must be kept at reset value. Refer to .

Field MMRQ writer - Mute mode request Writing 1 to this bit puts the USART in Mute mode and resets the RWU flag.

Field RXFRQ writer - Receive data flush request Writing 1 to this bit empties the entire receive FIFO i.e. clears the bit RXFNE. This enables to discard the received data without reading them, and avoid an overrun condition.

Field SBKRQ writer - Send break request Writing 1 to this bit sets the SBKF flag and request to send a BREAK on the line, as soon as the transmit machine is available. Note: When the application needs to send the break character following all previously inserted data, including the ones not yet transmitted, the software should wait for the TXE flag assertion before setting the SBKRQ bit.

Field TXFRQ writer - Transmit data flush request When FIFO mode is disabled, writing ’1’ to this bit sets the TXE flag. This enables to discard the transmit data. This bit must be used only in Smartcard mode, when data have not been sent due to errors (NACK) and the FE flag is active in the USART_ISR register. If the USART does not support Smartcard mode, this bit is reserved and must be kept at reset value. When FIFO is enabled, TXFRQ bit is set to flush the whole FIFO. This sets the TXFE flag (Transmit FIFO empty, bit 23 in the USART_ISR register). Flushing the Transmit FIFO is supported in both UART and Smartcard modes. Note: In FIFO mode, the TXFNF flag is reset during the flush request until TxFIFO is empty in order to ensure that no data are written in the data register.