The Arduino IDE emphasizes reading or writing individual pins, but I'd like to read all of the pins on a port at the same time. I know the chip can do this, but I don't know how to do it from C. Also, is there a handy way to set up all the pins on a port as inputs or outputs rather than using Pinmode on each pin? (Again, from C-- I know it can be done in assembler).
I'm using the Atmega43u4 breakout board from Adafruit, using the slightly modified version of Arduino 21 on this page: http://ladyada.net/products/atmega32u4breakout/
I want to read data from ports D and F, and then write it to the USB port. (I know two bits of port F are not available on this chip, but that's OK).
It seems like this would be an obvious question, but I haven't seen it discussed anywhere.