#define F_CPU 8000000UL
#include "sam.h"

extern uint32_t _estack; //0x20000400 (SRAM begin + STACK size)

int main(void);
void syst(void);

static void uart_init();
static void uart_send(char c);
static void uart_string(char *s);
uint8_t uart_receive(void);
void tester(uint32_t wert);
void fault(void);

static uint32_t array[] = {0x61c4, 0x2300, 0x469f};	//1, Toggle LED 2, load rgister with main Adress 3, return main
//-----------------------------------------------------------------------------
__attribute__ ((section(".vectors"))) const uint32_t table[] = 
{
	(uint32_t)&_estack,		//First, initialisize Stack
	(int) main,				//Call after Reset (and Stack)
	0,						//pfnNonMaskableInt_Handler
	(void*) fault,			//HardFault
	0,
	0,
	0,
	0,
	0,
	0,
	0,
	0,
	0,
	0,
	0,
	(void*) syst			//Interrupt Systick
};
//-----------------------------------------------------------------------------
int main(void)
{
	// Switch to 8MHz clock (disable prescaler)
	SYSCTRL->OSC8M.bit.PRESC = 0;
	
	// Turn on clock for PORT in BRIDGE B 
	PM->APBBMASK.reg |= PM_APBBMASK_PORT;
	
	uart_init(9600);
	uart_string("RUN\r\n");
	
	array[2] = 0x1234;
	uint32_t xx = 0x20000000 - 1;

	
	PORT->Group[0].DIRSET.bit.DIRSET = PORT_PA05;
	
	SysTick_Config(8000000UL); 
	
	uint8_t rec;
	uint32_t test = 0;	

	while (1)
	{
		if((SERCOM0->USART.INTFLAG.reg & SERCOM_USART_INTFLAG_RXC))
		{
			rec = SERCOM0->USART.DATA.reg;
			switch(rec)
			{
				case 'x': PORT->Group[0].OUTTGL.bit.OUTTGL = PORT_PA05; break;
				//case 'a': uart_string("PP: "); tester((uint32_t)*xx); uart_string("\r\n"); uart_string("PA: "); tester((uint32_t)xx); uart_string("\r\n"); break;
				case 'p': uart_string("EFFATA!!\r\n"); break;
				case 'f': asm volatile("mov PC, %0":"+r"((uint32_t)xx)); break;
				default: uart_string("Empfangen: "); uart_send(rec); uart_string("\r\n");
			}
		}
	}
}
//-----------------------------------------------------------------------------
void syst(void)
{
	//PORT->Group[0].OUTTGL.bit.OUTTGL = PORT_PA05;
	//uart_send('#');
}
//-----------------------------------------------------------------------------
static void uart_init()
{
  #define BAUDRATE 9600U
  uint64_t br = (uint64_t)65536 * (F_CPU - 16 * BAUDRATE) / F_CPU;
  
  //TX
  PORT->Group[0].DIRSET.reg = (1 << PIN_PA14);
  //PORT->Group[0].PINCFG[PIN_PA14].reg |= PORT_PINCFG_INEN;
  PORT->Group[0].PINCFG[PIN_PA14].reg |= PORT_PINCFG_PMUXEN;
  PORT->Group[0].PMUX[PIN_PA14>>1].bit.PMUXE = PORT_PMUX_PMUXE_C_Val; //PIN is even / gerade
  
  //RX
  PORT->Group[0].DIRCLR.reg = (1 << PIN_PA04);
  PORT->Group[0].PINCFG[PIN_PA04].reg |= PORT_PINCFG_INEN;
  PORT->Group[0].PINCFG[PIN_PA04].reg &= ~PORT_PINCFG_PULLEN;
  PORT->Group[0].PINCFG[PIN_PA04].reg |= PORT_PINCFG_PMUXEN;
  PORT->Group[0].PMUX[PIN_PA04>>1].bit.PMUXE = PORT_PMUX_PMUXE_C_Val; //PIN is even / gerade


  PM->APBCMASK.reg |= PM_APBCMASK_SERCOM0;

  GCLK->CLKCTRL.reg = GCLK_CLKCTRL_ID(SERCOM0_GCLK_ID_CORE) |
      GCLK_CLKCTRL_CLKEN | GCLK_CLKCTRL_GEN(0);

  SERCOM0->USART.CTRLA.reg =
      SERCOM_USART_CTRLA_DORD | SERCOM_USART_CTRLA_MODE_USART_INT_CLK |
      SERCOM_USART_CTRLA_RXPO(0) | SERCOM_USART_CTRLA_TXPO(1); //TXPO = PAD2 = 14 RXPO = PAD0 = 4

  SERCOM0->USART.CTRLB.reg = SERCOM_USART_CTRLB_RXEN | SERCOM_USART_CTRLB_TXEN |
      SERCOM_USART_CTRLB_CHSIZE(0/*8 bits*/);

  SERCOM0->USART.BAUD.reg = (uint16_t)br+1;

  SERCOM0->USART.CTRLA.reg |= SERCOM_USART_CTRLA_ENABLE;
}
//-----------------------------------------------------------------------------
static void uart_send(char c)
{
  while (!(SERCOM0->USART.INTFLAG.reg & SERCOM_USART_INTFLAG_DRE));
  SERCOM0->USART.DATA.reg = c;
}

//-----------------------------------------------------------------------------
static void uart_string(char *s)
{
  while (*s)
    uart_send(*s++);
}
//-----------------------------------------------------------------------------
uint8_t uart_receive(void)
{
	while (!(SERCOM0->USART.INTFLAG.reg & SERCOM_USART_INTFLAG_RXC));
	return SERCOM0->USART.DATA.reg;
}
/*
static char* calca32(uint32_t wert)
//V2.0
{
	uint8_t i = 10;
	static char rueck[11];

	while(i--)
	{
		rueck[i] = (wert % 10) + 48;
		wert = wert / 10;
	}
	return rueck;
}
*/
void tester(uint32_t wert)
{
	uint32_t i = 32;

	while(i--)
	{
		if(wert & (1<<i)) uart_send('1');
		else uart_send('0');
	}
}

void fault(void)
{
		uart_string("FAULT\r\n");
	
		main();

}