if ((TIFR1 & _BV(ICF1)) == 0)
return;
- sei();
- icp = ICR1;
cli();
+ icp = ICR1;
+ sei();
rising = TCCR1B & _BV(ICES1);
/* change the edge type */
TCCR1B ^= _BV(ICES1);
- /* clear the flag */
+ /* clear the flag by writing a one */
TIFR1 = TIFR1 | _BV(ICF1);
diff = icp - icp_prev;