Lpc2000

How important is the value 1.5k for the pull-up?  Would another value
work, like 2.2K?  I see in the spec it's quite serious about the 1.5k
value, but doesn't really seem to explain why (other than time to
pull-up).  Has anyone played with this?

I'm assuming the LPC2148 doesn't have internal pullup?

From: "seangra"
> How important is the value 1.5k for the pull-up?  Would another value
> work, like 2.2K?  I see in the spec it's quite serious about the 1.5k
> value, but doesn't really seem to explain why (other than time to
> pull-up).  Has anyone played with this?

It's from the USB spec, based on maximum length cabling and required maximum
R-C time for enumeration. Don't play around with it, be sure and use 1K5.

> I'm assuming the LPC2148 doesn't have internal pullup?

Not likely, because the chip process variation is more than the required
accuracy.

Regards,
Arie de Muynck