NANO and PCINT

Hi,
I read many tuto about PCINT and ATMEGA328 but this simple code does not run.
“i” remains 0 while pin8 changed.
Where is my error?
I’m using ARDUINO NANO V3. Nothing connected just one wire to connect pin8 to ground.
I think some other registers have to be updated.
Thanks.
Vince.

#include <avr/interrupt.h>

volatile int i = 0;
void setup() {
   pinMode(8,INPUT_PULLUP);
   cli();
   PCIFR = B00000000; // clear all interrupt flags
   PCICR = B00000001; // enable PCINT 0 PORT
   sei();
  Serial.begin(9600);
  while(!Serial){}
}
ISR(PCINT0_vect) {
  i++;
}

void loop() {
  // put your main code here, to run repeatedly:
  Serial.print("Output 8 : ");
  Serial.println(digitalRead(8));
  Serial.print("i = ");
  Serial.println(i);
  delay(1000);
}

Result :

Output 8 : 1
i = 0
Output 8 : 0
i = 0
Output 8 : 1
i = 0
Output 8 : 0
i = 0
Output 8 : 1
i = 0
PCIFR = B00000000; // clear all interrupt flags
PCMSK0 = 1<<PCINT0;    <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
PCICR = B00000001; // enable PCINT 0 PORT

Thank you man. :wink:

Vince.