Lpc2000

Hi Vern,

> What I found using a logic analyzer, sampling at 500MHz, is that the
> time between my external indication going high and the time my signal
> pin goes high is about ~230ns.  I am running my ARM at 58.9MHz (I will
> be changing to 60MHz when parts get in).  I realize that a couple
> clock cycles get wasted raising my signal pin and a couple may get
> lost if I am in the 'while' jump, but why is it taking so long to
> register the external input?  Does using the mask register carry any
> overhead, seems silly if it did?

An interesting experiment might be to compare the response of using an
external interrupt pin set as a FIQ.  It seems it should be slower than
polling FIOPIN, but curious as to the results.

Joel