Dear All
Please advice that we can connect the HD44780 compatible LCD to Xmega 128A1 micro controller which is i/o voltage level is 3.3v
I mean 3.3v Xmega i/o's can drive the 5v LCD data port without using any voltage sifter booster
Yes you can. Just apply +5V for Supply VDD of LCD. You can use I/O ports of XMEGA as it is. The LCD is able to detect 3.3V as Logic 1. So you can do your LCD task without using any kind of voltage converter.