Due to the slow nature of digitalRead and digitalWrite, I am using port manipulation methods to speed things up. But this alters the entire register So if I use this PORTB = B11111111; Will this have an effect on the external oscillator ports PB7 and PB6 ? Or are these overruled by cetting certain fuses in the bootloader?
Also for ease of programming I want to use port PD1 ( TX ) as an output, since this is also possible on a regular UNO I looked at its schematic and saw I would just need to put a 1k resistor on tx and rx before plug SV1, does this pose any limitation on the output load, if so would a 470 ohm resistor for the leds be a problem? This problem would only occur when reprogramming the 328 in circuit or during serial communication right?