topic Re: LPC845 default state of an output GPIO port in LPC Microcontrollers

LPC845 default state of an output GPIO port

tyassin1 — Fri, 24 Mar 2023 15:47:05 GMT

Hi,

I have tried to find the answer what the state of a standard GPIO is when it is changed to an output?
I can find in the datasheet that per default a GPIO is an inpout with a weak pull-up. But what is the output state when I change this in the DIR[0:1] register and before is set the output?

Thank you

Re: LPC845 default state of an output GPIO port

_Leo_ — Fri, 24 Mar 2023 19:49:55 GMT

Hi,

Thank you so much for your interest in our products and for using our community.

Indeed, in the documentation there is no mention of the default state of an output GPIO port, however, the state of a port's output bits can be read from its SET register. Please refer to the 12.6.1 Reading pin state section of the user manual for more detail.

Hope it helps you.

Have a nice day!

Re: LPC845 default state of an output GPIO port

tyassin1 — Fri, 24 Mar 2023 20:18:12 GMT

Hi,

Thank you for the answer.

I was more interested in what state the output will be when it is changed from input to output. As I have some devices with enable pins, where they turn ON withan active high. So I guess I can fix this with a "stong" pull-down and then when the GPIO is changed to an output I would guess that the output is low. But to be sure and also because I cannot find it stated anywhere, I just ask this question in this forum.