open drain outputs

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YahooArchive
Posts: 1462
Joined: Fri Oct 19, 2012 5:11 am

open drain outputs

Post by YahooArchive »

> I have ARMWeb rev2,3 beta board. using ARMWeb 7.36
>
> I don't seem to be able to program io port 11 (on pin 37 of the 2138),
> is there something special
> about this pin? So far I have only tried using the basic SPIOUT
command.

This pin is open drain (help file, NXP spec sheet or user manual), so
it can not pullup. So to use it as an output, you will need to
provide a pullup resistor.



YahooArchive
Posts: 1462
Joined: Fri Oct 19, 2012 5:11 am

Re: open drain outputs

Post by YahooArchive »

thanks... I should of looked at the docs more carefully!

On Jan 4, 2009, at 2:23 PM, basicnode wrote:

> > I have ARMWeb rev2,3 beta board. using ARMWeb 7.36
> >
> > I don't seem to be able to program io port 11 (on pin 37 of the
> 2138),
> > is there something special
> > about this pin? So far I have only tried using the basic SPIOUT
> command.
>
> This pin is open drain (help file, NXP spec sheet or user manual), so
> it can not pullup. So to use it as an output, you will need to
> provide a pullup resistor.

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