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Pulling P0.2 or P0.3 high on LPC2148 only with a pull-up-resistor?

Started by c_budelmann July 26, 2008
Hi,

I'm working with a LPC2148, and had some problems using P0.2 and P0.3
as general IO-pins. Pulling them high did not work. On a LPC2148-board
from Olimex the code worked fine, so I added two pull-up-resistors to
my circuit (On the Olimex-board, there are some resistors for the
IC-interface.).

Now it works, but is it a bug in the device or just a feature I cannot
find in the datasheet?

Cheers,
Christoph

An Engineer's Guide to the LPC2100 Series

Hello.
It is a feature, it is because I2C lines, even if you configure them as simple IOPIN, only have sink transistors.
Cheers,

Daniel.

To: l...From: c...@budelmann.orgDate: Sat, 26 Jul 2008 12:22:02 +0000Subject: [lpc2000] Pulling P0.2 or P0.3 high on LPC2148 only with a pull-up-resistor?

Hi,I'm working with a LPC2148, and had some problems using P0.2 and P0.3as general IO-pins. Pulling them high did not work. On a LPC2148-boardfrom Olimex the code worked fine, so I added two pull-up-resistors tomy circuit (On the Olimex-board, there are some resistors for theIC-interface.).Now it works, but is it a bug in the device or just a feature I cannotfind in the datasheet?Cheers,Christoph

_________________________________________________________________
Herramientas para combatir la crisis. MSN Dinero
http://dinero.es.msn.com/


It is spelled out very clear in the manual. On page 69, both pins have
a footnote of [3]. On page 74, footnote [3] says that 'requires
external pull-ups to provide an output functionality'.

--- In l..., "c_budelmann" wrote:
>
> Hi,
>
> I'm working with a LPC2148, and had some problems using P0.2 and P0.3
> as general IO-pins. Pulling them high did not work. On a LPC2148-board
> from Olimex the code worked fine, so I added two pull-up-resistors to
> my circuit (On the Olimex-board, there are some resistors for the
> IC-interface.).
>
> Now it works, but is it a bug in the device or just a feature I cannot
> find in the datasheet?
>
> Cheers,
> Christoph
>

See if u r making this mistake anywhere....

ensure you register in this site... keep a watch...

Tell avadoot swami also,,,


Natarajan

--- On Sat, 7/26/08, Sutton Mehaffey wrote:

From: Sutton Mehaffey
Subject: [lpc2000] Re: Pulling P0.2 or P0.3 high on LPC2148 only with a pull-up-resistor?
To: l...
Date: Saturday, July 26, 2008, 8:08 AM

It is spelled out very clear in the manual. On page 69, both pins have
a footnote of [3]. On page 74, footnote [3] says that 'requires
external pull-ups to provide an output functionality' .

--- In lpc2000@yahoogroups .com, "c_budelmann" wrote:
>
> Hi,
>
> I'm working with a LPC2148, and had some problems using P0.2 and P0.3
> as general IO-pins. Pulling them high did not work. On a LPC2148-board
> from Olimex the code worked fine, so I added two pull-up-resistors to
> my circuit (On the Olimex-board, there are some resistors for the
> IC-interface. ).
>
> Now it works, but is it a bug in the device or just a feature I cannot
> find in the datasheet?
>
> Cheers,
> Christoph
>