On Sep 7, 2006, at 9:59 AM, Ben Hui wrote:

Hi, this may be† a very trivial question, maybe so trivial that the twiki and mailing list donít mention it at all. There is a small button on connex400 board. what is the use of it? Is it to reset the device?

Yup.† It's a hardware reset button, connected to the PXA255's nRESET line.