/**
* \brief Configures an USART baudrate when USART_MODE=SPI.
*
*
* \param pUsart Pointer to the USART peripheral to configure.
* \param baudrate Baudrate at which the USART should operate (in Hz).
* \param masterClock Frequency of the system master clock (in Hz).
*/
static void USART_SPI_SetBaudrate(Usart *pUsart,
uint32_t baudrate,
uint32_t masterClock)
{
unsigned int CD, FP;
/* Configure baudrate*/
CD = (masterClock / baudrate);
FP = ((masterClock / baudrate) - CD);
pUsart->US_BRGR = (US_BRGR_CD(CD) | US_BRGR_FP(FP));
}
/**
* \brief Configures an USART peripheral with the specified parameters.
*
*
* \param usart Pointer to the USART peripheral to configure.
* \param mode Desired value for the USART mode register (see the datasheet).
* \param baudrate Baudrate at which the USART should operate (in Hz).
* \param masterClock Frequency of the system master clock (in Hz).
*/
void USART_Configure(Usart *pUsart,
uint32_t mode,
uint32_t baudrate,
uint32_t masterClock)
{
unsigned int CD, FP, BaudError, OVER, ActualBaudRate;
/* Reset and disable receiver & transmitter*/
pUsart->US_CR = US_CR_RSTRX | US_CR_RSTTX
| US_CR_RXDIS | US_CR_TXDIS | US_CR_RSTSTA;
pUsart->US_IDR = 0xFFFFFFFF;
/* Configure baudrate*/
BaudError = 10;
OVER = 0;
// Configure baud rate
while (BaudError > 5)
{
CD = (masterClock / (baudrate * 8*(2-OVER)));
FP = ((masterClock / (baudrate * (2-OVER)) ) - CD * 8);
ActualBaudRate = (masterClock/(CD*8 + FP))/(2-OVER);
BaudError = (100-((baudrate*100/ActualBaudRate)));
if (BaudError > 5)
{
OVER++;
if(OVER>=2)
{
assert( 0 ) ;
}
}
}
pUsart->US_BRGR = ( US_BRGR_CD(CD) | US_BRGR_FP(FP));
/* Configure mode*/
pUsart->US_MR = (mode | (OVER << 19) );
// Enable receiver and transmitter
pUsart->US_CR = US_CR_RXEN | US_CR_TXEN;
/* Disable buffering for printf(). */
#if ( defined (__GNUC__) && !defined (__SAMBA__) )
setvbuf(stdout, (char *)NULL, _IONBF, 0);
#endif
}
