cyberhs:
64 Mhz ???
leo72:
Circuito PLL
Esatto, e Timer4 ha il clock a 64 Mhz, è una "feature" in più che ha il ATmega32U4 ... se guardi il datasheet, al paragrafo 15 dove descrive il : 10-bit High Speed Timer/Counter4 ...
"Timer/Counter4 is a general purpose high speed Timer/Counter module, with three independent Output Compare Units, and with enhanced PWM support.
The Timer/Counter4 features a high resolution and a high accuracy usage with the lower prescaling opportunities. It can also support three accurate and high speed Pulse Width Modulators using clock speeds up to 64 MHz."
Guglielmo