//usart.c
#include "AT91SAM7S256.h"
#include "usart.h"

AT91PS_PIO    u_pPioA   = AT91C_BASE_PIOA;
AT91PS_PMC    u_pPMC    = AT91C_BASE_PMC;
AT91PS_USART  u_pUSART0 = AT91C_BASE_US0;
AT91PS_USART  u_pUSART1 = AT91C_BASE_US1;
AT91PS_PDC    u_pPDC0   = AT91C_BASE_PDC_US0;
AT91PS_PDC    u_pPDC1   = AT91C_BASE_PDC_US1;
AT91PS_MC     u_pMC     = AT91C_BASE_MC;

void InitUSART0(void)
{

  u_pPioA->PIO_PDR = BIT0 | BIT1;   //Disables the PIO from controlling the corresponding pin (enables peripheral control of the pin).
  u_pPioA->PIO_ASR = BIT0 | BIT1;   //Assigns the I/O line to the peripheral A function.
  u_pPioA->PIO_BSR = 0;             // peripheral B function set to "no effect"
  //enable the clock of USART
  u_pPMC->PMC_PCER = 1<<AT91C_ID_US0;

  //Reset receiver and transmitter
  u_pUSART0->US_CR = AT91C_US_RSTRX | AT91C_US_RSTTX | AT91C_US_RXDIS | AT91C_US_TXDIS ;

  //set baud rate divisor register
  u_pUSART0->US_BRGR = 78; //((47923200)/38400x16)

  //write the Timeguard Register
  u_pUSART0->US_TTGR = 0;

  //Set the USART mode
  u_pUSART0->US_MR = 0x08c0;

  //Enable the RX and TX PDC transfer requests
 // u_pPDC0->PDC_PTCR = AT91C_PDC_TXTEN | AT91C_PDC_RXTEN;

  //Enable usart - enable RX receiver and TX transmiter
  u_pUSART0->US_CR = 0x50;

}

void InitUSART1(void)
{

  u_pPioA->PIO_PDR = BIT5 | BIT6;  //Disables the PIO from controlling the corresponding pin (enables peripheral control of the pin).
  u_pPioA->PIO_ASR = BIT5 | BIT6;  //Assigns the I/O line to the peripheral A function.
  u_pPioA->PIO_BSR = 0;             // peripheral B function set to "no effect"
  //enable the clock of USART
  u_pPMC->PMC_PCER = 1<<AT91C_ID_US1;

  //Reset receiver and transmitter
  u_pUSART1->US_CR = AT91C_US_RSTRX | AT91C_US_RSTTX | AT91C_US_RXDIS | AT91C_US_TXDIS ;

  //set baud rate divisor register
  u_pUSART1->US_BRGR = 78; //((47923200)/38400x16)

  //write the Timeguard Register
  u_pUSART1->US_TTGR = 0;

  //Set the USART mode
  u_pUSART1->US_MR = 0x08c0;

  //Enable the RX and TX PDC transfer requests
  //u_pPDC1->PDC_PTCR = AT91C_PDC_TXTEN | AT91C_PDC_RXTEN;

  //Enable usart:enable Transmitter und Receiver, if both are disabled.
  u_pUSART1->US_CR = 0x50;

}
void read_write_ch(char* ch){
	int i=0;
	while((u_pUSART1->US_CSR & AT91C_US_RXRDY)==1){
		ch[i]= u_pUSART1->US_RHR;
		if(ch[i] != '\0' ){
			while (!(u_pUSART0->US_CSR&AT91C_US_TXRDY));
			u_pUSART0->US_THR = ch[i];
		}
		i++;

	}
}

int main (void)
{
	 char* nmea_data = 0x0;
	InitUSART0();
	InitUSART1();
	while (1){
		read_write_ch(nmea_data);
	}
}