#include "stm32l0xx.h"

// Define the LED pin and port
#define LED_PIN   (1 << 3)   // PA3
#define LED_PORT  GPIOA

void SystemClock_Config(void)
{
    // Configure the system clock as needed; this is a placeholder
    // The default HSI clock configuration should work for this example
}

void initGPIO(void)
{
    // Enable GPIOA clock
    RCC->IOPENR |= RCC_IOPENR_GPIOAEN;
    
    // Configure PA3 as output
    GPIOA->MODER &= ~(GPIO_MODER_MODE3);      // Clear mode bits
    GPIOA->MODER |= GPIO_MODER_MODE3_0;       // Set PA3 as general-purpose output mode
    GPIOA->OTYPER &= ~(GPIO_OTYPER_OT_3);       // Set PA3 as push-pull
    GPIOA->OSPEEDR |= GPIO_OSPEEDER_OSPEED3;    // Set PA3 as high speed
    GPIOA->PUPDR &= ~(GPIO_PUPDR_PUPD3);       // No pull-up, pull-down
}

int main(void)
{
    // Initialize system
    HAL_Init();         // Initialize HAL (if needed)
    SystemClock_Config();

    // Initialize GPIO
    initGPIO();

    // Turn on the LED
    GPIOA->ODR |= LED_PIN;

    // Main loop
    while (1)
    {
        // Do nothing, LED is on
    }
}