USART transmit data register
TDR | Transmit data value Contains the data character to be transmitted. The USART_TDR register provides the parallel interface between the internal bus and the output shift register (see Figure1227). When transmitting with the parity enabled (PCE bit set to 1 in the USART_CR1 register), the value written in the MSB (bit 7 or bit 8 depending on the data length) has no effect because it is replaced by the parity. Note: This register must be written only when TXE/TXFNF=1. |