Could you please clarify the following point? Here is the example of a keyboard matrix scan for non-Xmega mcu: https://extremeelectronics.co.in...
One have to set all columns to high Z state, and then set one of the columns to OUTPUT LOW. However Xmega allows to set all columns to Wired-AND OUTPUT HIGH. And then one of the columns can be set to Wired-AND OUTPUT LOW to detect key presses on this column. Is it right? I don't understand what is the advantage of Xmega. Could this scheme be improved significantly?
Also I have a related question. A three-stated pins of non-Xmega mcu allows to use charlieplexing for leds and key switches. Does Xmega provides some advantages for multiplexing or matrix schemes?