How to disconnect the input buffer?

[nordev]

It seems like the only way to disconnect the input buffer is using ANAEN, but I know this post says that ANAEN is fake. So I am wondering if there is a way to disconnect the input buffer for a non-analog input. I have a wrongly connected trace on my custom PCB that goes to a digital GPIO and I want to see if I can disconnect the buffer so that it doesn't turn on the NMOS & PMOS at the same time and consume unnecessary power. 

I am just looking for general help and instructions for disconnecting the input buffer.

Thanks

[Vidar Berg]

Hello,

GPIOs are configured as inputs with the input buffer disconnected on reset as can be seen from the screenshot below. This means you can skip configuration of unused pins in your app. You can also use the nrf_gpio_cfg_default() function if you need to configure a pin back to its reset state.

(Link to PIN_CNF[n])

[nordev]

Thank you Vidar - very helpful.

When the input buffer is disconnected, is anything done internally to keep the CMOS from floating & turning both FETs on simultaneously?

Also, how do you configure drive strength?

[Vidar Berg]

I'm not familiar with how it works internally, but it is fine to leave the input floating when the input buffer is disconnected. It will not lead to any leakage current.

The drive strength is configured in the same register I linked to earlier. It can be set directly or through the nrf_gpio_cfg() call.

[nordev]

Thanks Vidar!

EDIT: found the answer explaining drive strength in this forum post here

Please tell me if I am wrong, but it seems like nrf_gpio_cfg() just changes what setting 1 or 0 means, and the actual strength (0 or 1) has to be configured with some other function. 

If this is correct, how do I actually set the drive strength to 0 or 1?