#define GPIO_pin 5
uint32_t Freq = 0;

void setup() 
{
  pinMode(GPIO_pin,OUTPUT);
  Serial.begin(115200);
  Freq = getXtalFrequencyMhz();
  Serial.print( "Xtal Freq = ");
  Serial.print(Freq);
  Serial.println(" Mhz");
  Freq = getXtalFrequencyMhz();
  Serial.print( "Xtal Freq = ");
  Serial.print(Freq);
  Serial.println(" Mhz");
  Freq = getApbFrequency();
  Serial.print( "Abp Freq = ");
  Serial.print(Freq);
  Serial.println(" hz");

  
}

void loop() {
  digitalWrite(GPIO_pin, 1);
  digitalWrite(GPIO_pin, 0);
}