/**
 ******************************************************************************
 * @file           : main.c
 * @author         : Fernando Hermosillo Reynoso
 * @brief          : Main program body
 ******************************************************************************
 */

#include <stdint.h>
#include "stm32f103xb.h"

void delay_ms(uint16_t ms) {
	volatile unsigned long t = 0;
	for(uint16_t i = 0; i < ms; i++)
	{
		for(t = 0; t < 800; t++);
	}
}

int main(void)
{
	// Enable GPIOC clock
	RCC->APB2ENR |= 1UL << 4;

	// Set PC13 as 2MHz push-pull output
	GPIOC->CRH &= ~(0x0FUL << 20); // MODE13=00, CNF13=00
	GPIOC->CRH |= 1UL << 21; // MODE13 = 10 (2MHz output)


	// Loop
	while (1)
	{
		GPIOC->ODR ^= (1UL << 13); // Set to zero
		delay_ms(500);
	}
}