AVR-Chat

Peter Gargano wrote:
> Russell Shaw wrote:
> 
>>If you look at fig.182 of the ATmega16 data sheet, you'll find that VIHmin=1.9V,
>>so the 3V spec must be at some 3-5 sigma distribution point.
> 
> 
> Russell, thanks for that. Also fig. 192 and 193 of the M64 datasheet 
> say the same thing.
> 
> Again, on the M64 data sheet, this is quite different to the DC 
> Characteristics (on page 327) where
> 
>                           min.     typ.    max.
>                          ------------------------------
> VIL Input Low Voltage    -0.5             0.2 VCC
> VIH Input High Voltage    0.6 VCC         VCC + 0.5 V

You could enable the input pullup resistor, or add an external one.
Also look at the datasheet for the device driving it, and check if
the 2.4V output limit only happens at higher load current.