Open-drain GPIO

[Anonymous]

Hi,

Is it possible to configure a GPIO as open-drain? It doesn't seem like this configuration is allowed through the SDK (2.0) at the moment. Will it be added in the future?

Would the following workaround accomplish open-drain functionality?

     -Configure GPIO as output enable and set low when signal needs to be low.

     -Configure GPIO as output disable (so that it is high-Z) and allow external pullup to set the signal high.

Thanks,

Mike

[MichaelF_56]

If I'm not mistaken, IO like the LEDs, Serial Ports, etc. are already open drain and the pull-ups pull the signal high while the HW drives it low (i.e. never drives high, but floats the output pad leaving the pull-up to pull the line high).

I will need to check with the team to confirm that all of the IO is open drain.

[asridharan · Accepted solution]

> Would the following workaround accomplish open-drain functionality?

Yes, this will work, though you might want to disable both input and output for high-Z.