bitstream reader

Hi

I've been working on a project that require me read a repetitive bit stream of 64 bit on a single pin.
i was doing this on AVR using the external interrupt pin but i need to do it with arduino.

any help ?
thank you all as it's my first topic here !

"i was doing this on AVR using the external interrupt pin but i need to do it with arduino."

How are the two different?

You might want to check out sparkfun.com they have a "Bus Pirate" that can do stuff like that (I have not put mine together yet but it seems it could read all sorts of formats).