/*
 * 	startup.c
 *
 */
#define		SIMULATOR

#define 	GPIO_D				0x40020C00
#define 	GPIO_MODER			((volatile unsigned int *)		(GPIO_D))
#define 	GPIO_OTYPER			((volatile unsigned short *)	(GPIO_D + 0x4))
#define 	GPIO_PUPDR			((volatile unsigned int *)		(GPIO_D + 0xC))
#define 	GPIO_IDR_LOW		((volatile unsigned char *)		(GPIO_D + 0x10))
#define 	GPIO_IDR_HIGH		((volatile unsigned char *)		(GPIO_D + 0x11))
//define 	GPIO_IDR_reserve
#define 	GPIO_ODR_LOW		((volatile unsigned char *)		(GPIO_D + 0x14))
#define 	GPIO_ODR_HIGH		((volatile unsigned char *)		(GPIO_D + 0x15))
//define 	GPIO_ODR_reserve

#define  	STK_CTRL  			((volatile unsigned int *)(0xE000E010))
#define  	STK_LOAD  			((volatile unsigned int *)(0xE000E014))
#define  	STK_VAL  			((volatile unsigned int *)(0xE000E018))

#ifdef		SIMULATOR
#define		DELAY_COUNT		100
#else
#define		DELAY_COUNT		1000000
#endif

int systick_flag = 1;
static volatile int delay_count;

void startup(void) __attribute__((naked)) __attribute__((section (".start_section")) );

void startup ( void ){
__asm volatile(
	" LDR R0,=0x2001C000\n"		/* set stack */
	" MOV SP,R0\n"
	" BL main\n"				/* call main */
	"_exit: B .\n"				/* never return */
	) ;
}
void delay_250ns( void ) {
 /* SystemCoreClock = 168000000 */
	 *STK_CTRL = 0;
	 *STK_LOAD = ( (168/4) -1 );
	 *STK_VAL = 0;
	 *STK_CTRL = 5;

	while( (*STK_CTRL & 0x10000 )== 0 ){

	}
	*STK_CTRL = 0;
}
void delay_1mikro( void ){
	// sYSTEMcOREcLOCK = 168000000
	*STK_CTRL = 0;
	*STK_LOAD = ( 168 - 1);
	*STK_VAL = 0;
	*STK_CTRL = 7;
	systick_flag = 0;
}
void delay(unsigned int count){
		delay_count = count;
		if( count == 0){
			return;
		}
		delay_1mikro();
}
void systick_irq_handler(void){
	*STK_CTRL = 0;
	delay_count--;
	if( delay_count > 0){
		delay_1mikro();
	}
	else{
		systick_flag = 1;
	}

}
void init_app( void){
	/* Initiera port D */
	* ( (unsigned long *) 0x40020C00) = 0x00005555;
	/* Initiera undantagsvektor */
	*((void (**)( void )) 0x2001C03C) = systick_irq_handler;
}
void main(void){
	init_app();
	delay( DELAY_COUNT );
	*GPIO_ODR_LOW = 0XFF;
	while(1){
		if( systick_flag == 1 ){
			break;
			//Här placeras kod som kan utföras under väntetiden
		}
	//Här finns den kod som "väntar på time-out
	}
	*GPIO_ODR_LOW = 0;
	//
}