tiny84 .. strange "millis()" function results with interrupts

Using Arduino Programming Questions
1

hi to all,

this is my loop: (tiny84 8MHz)
{
Sleepy::loseSomeTime(10000); // 10 sec, sleep
g_currentMillis = millis();
mySerial.println(g_currentMillis);
}

this is the ISR of my pin_change interrupt:
void ISR_wakeup_fototransistor()
{
if(digitalRead(opto_PIN)==1) g_flg_lampeggio=1;
}

when interrupts occurs rapidly the millis() are unpredictable ( increments few SECONDS each interrupts)

this works well if NO INTERRUPTS occours.

Any idea ???

thanks in advance
best regards to all.
Mauro IK1WVQ

2

Please use code tags. If you want help with a sketch, please include the whole sketch.

How is the ISR installed? In particular, is it edge or level triggered?

3