#include <stdint.h>

// Base addresses for RCC and GPIOA
#define RCC_BASE       0x40021000
#define GPIOA_BASE     0x40010800

// RCC Registers
#define RCC_APB2ENR    *(volatile uint32_t *)(RCC_BASE + 0x18)

// GPIOA Registers
#define GPIOA_CRL      *(volatile uint32_t *)(GPIOA_BASE + 0x00)
#define GPIOA_ODR      *(volatile uint32_t *)(GPIOA_BASE + 0x0C)

void delay(volatile uint32_t count) {
    while (count--) {
        // Simple delay loop
    }
}

int main(void) {
    // 1. Enable clock for GPIOA
    RCC_APB2ENR |= (1 << 2);  // Set bit 2 to enable GPIOA clock

    // 2. Configure PA0 as output (General purpose output push-pull, max speed 2 MHz)
    GPIOA_CRL &= ~(0xF << (0 * 4)); // Clear configuration for PA0
    GPIOA_CRL |=  (0x2 << (0 * 4)); // Set PA0 to output mode, max speed 2 MHz

    while (1) {
        // 3. Toggle PA0
        GPIOA_ODR ^= (1 << 0);  // Toggle bit 0 (PA0)

        // 4. Add delay
        delay(1000000);  // Adjust the value for desired delay duration
    }

    return 0;
}