Impedances required for re-layout

[SCaron]

I have a iMX233 micro-computer which I'm re-laying out into a different technology. I was wondering if there were any controlled impedances (50 ohm or 100 ohm differential lines) that I need to be aware of.

[Kean]

First, the USB port, but as it is USB2.0 it isn't really too critical depending on your application.
Second, the DDR clock differential pair, as I know that Olimex had problems with that on the Micro, which was actually solved by removing the termination resistor.
You will need to do trace length matching for the rest of the DDR signals.