// Question: Does pin 19 interrupt work and can PORTD be read ? 
// Answer: Yes

int interruptPin = 19;
volatile byte count = 0; 
byte old_count = 0;

void setup()
{
  Serial.begin(115200);
  Serial.println("Start");
  
  pinMode(interruptPin, INPUT);
  attachInterrupt(digitalPinToInterrupt(interruptPin), on_change_state, CHANGE);
}

void loop()
{
  // The interrupts are kept running,
  // while using the variables.
  // That means that the variables
  // can change during these lines of code.
  if(count != old_count)
  {
    Serial.print(count);
    old_count = count;

    Serial.print("  0x");
    byte reg = PIND;
    if(reg < 0x10)
      Serial.print("0");
    Serial.print(reg,HEX);

    Serial.print("  ");
    int bit = bitRead(PIND,PD2);
    Serial.print(bit == 0 ? "low" : "high");

    Serial.println();
  }
}

void on_change_state() 
{
  count++;
}