Posted on May 17, 2011 at 13:40The USART Data Register (DR) is 16-bits wide, to accommodates all 9 bits (
D0
..
D8
)
You should always write the DR as an ''unsigned short'' or ''u16'', if using DMA the 9-bit mode would require you send Half Words, not Bytes.
-Clive
/*******************************************************************************
* Function Name : USART_SendData
* Description : Transmits single data through the USARTx peripheral.
* Input : - USARTx: Select the USART or the UART peripheral.
* This parameter can be one of the following values:
* - USART1, USART2, USART3, UART4 or UART5.
* - Data: the data to transmit.
* Output : None
* Return : None
*******************************************************************************/
void USART_SendData(USART_TypeDef* USARTx, u16 Data)
{
/* Check the parameters */
assert_param(IS_USART_ALL_PERIPH(USARTx));
assert_param(IS_USART_DATA(Data));
/* Transmit Data */
USARTx->DR = (Data & (u16)0x01FF);
}
