AVR-Chat

On Wed, Sep 01, 2004 at 05:14:11AM -0000, Yang Wang wrote:

> Thanks for the reply. Do we have to pull up the PEN pin? I didn't
> connect it to anything, and it was high as I measured when the
> program was running, so it looks like it has an internal pull-up. But
> I think this is probably going to be worth of a try.

Figure 22 on my copy of the datasheet (Page 48) shows an internal
pull-up on PEN to Vcc, so you can safely leave PEN unconnected if it
is not used.  Also, for example, see the datasheet for the AT90CAN128
which is a "pin compatible" device and describes that pin position as
NC (Not Connected, leave unconnected - may be used in a future
revision).

-Brian
-- 
Brian Dean
http://www.bdmicro.com/