I'm prototyping on a Arduino Duemilanove a project that uses Ports manipulation at fast rates. But since I need more pins (54 actually), I wonder if the direct access to port registers of the supplementary ports like PORTE, PORTF, PORTG... etc... was available on the Mega 2560 ?
On "Port manipulation" page, it is only said that mapping is different from Atmega328 to Atmega1280.
I did some researches on the web and found the Atmega 1280 pin mapping (same as Atmega2560), but couldn't find someone who really used the registers in his/her code in order to manipulate thoses extra pins/ports.
So my question is simple : can I access (read/write) all the Arduino Mega 2560 pins directly as Registers ?