digitalWriteFast does not appear to work on AVR4809

[paulskirk53]

I included the library :

#include <digitalWriteFast.h>

The code snippet below toggles a Led:

void lightup()
{
  for (int i = 0; i < 10; i++)
  {
    digitalWrite(ledpin, HIGH);
    delay(500);
    digitalWrite(ledpin, LOW);
    delay(500);
  }

But the code below does not

void lightup()
{
  for (int i = 0; i < 10; i++)
  {
    digitalWriteFast(ledpin, HIGH);
    delay(500);
    digitalWriteFast(ledpin, LOW);
    delay(500);
  }

Perhaps I missed something?