// Loesung zu Termin 5
// Aufgabe 1
// Namen: ___________; ____________
// Matr.: ___________; ____________
// vom:   ___________

#include <sam.h>

#define PA12 1u << 12
#define PA13 1u << 13

int main(void)
{
  PIOA->PIO_PDR = PA12 | PA13;
  PIOA->PIO_ABSR &= ~(PA12 | PA13);

  PMC->PMC_PCER0 = 1u << ID_USART1;

  USART1->US_CR = US_CR_RXDIS | US_CR_TXDIS | US_CR_RSTRX | US_CR_RSTTX; // Receiver and transmitter resetted and disabled
  USART1->US_PTCR = US_PTCR_RXTDIS | US_PTCR_TXTDIS;                     // Disables the PDC receiver & transmitter channel requests. (DMA)

  USART1->US_MR = US_MR_USART_MODE_NORMAL | // Normal mode
                  US_MR_USCLKS_MCK |        // Master Clock is selected
                  US_MR_CHRL_8_BIT |        // Character length is 8 bits
                  US_MR_PAR_ODD |           // Odd parity
                  US_MR_NBSTOP_2_BIT |      // 2 stop bit
                  US_MR_CHMODE_NORMAL;      // Normal channel mode

  /* int version (about two decimal points precision) */
  uint32_t cd = SystemCoreClock * 10 / 16 * 10 / 9600;
  uint32_t cd_int = cd / 100;
  uint32_t cd_frac = (cd % 100 * 8 + 50) / 100;
  USART1->US_BRGR = cd_frac & US_BRGR_FP_Msk << US_BRGR_FP_Pos | cd_int & US_BRGR_CD_Msk << US_BRGR_CD_Pos;

  USART1->US_CR = US_CR_RXEN | US_CR_TXEN;         // Receiver and transmitter enabled
  USART1->US_PTCR = US_PTCR_RXTEN | US_PTCR_TXTEN; // Enable the PDC receiver & transmitter channel requests. (DMA)

  return 0;
}