#include "stm32c0xx.h"
 
void delay_ms(uint32_t ms) {
    for(uint32_t i = 0; i < ms * 1600; i++) {
        __NOP();
    }
}
 
int main(void) {
    // Enable GPIOA clock
    RCC->IOPENR |= RCC_IOPENR_GPIOAEN;
 
    // Set PA5 and PA6 as outputs
    GPIOA->MODER &= ~(GPIO_MODER_MODE5_Msk | GPIO_MODER_MODE6_Msk); // Clear
    GPIOA->MODER |=  (1 << GPIO_MODER_MODE5_Pos) | (1 << GPIO_MODER_MODE6_Pos); // Output mode
 
    while (1) {
        // Turn ON Positive logic LED (PA5 HIGH)
        GPIOA->ODR |= (1 << 5);
        // Turn OFF Negative logic LED (PA6 HIGH = OFF)
        GPIOA->ODR |= (1 << 6);
        delay_ms(500);
 
        // Turn OFF Positive logic LED (PA5 LOW)
        GPIOA->ODR &= ~(1 << 5);
        // Turn ON Negative logic LED (PA6 LOW = ON)
        GPIOA->ODR &= ~(1 << 6);
        delay_ms(500);
    }
}