GPIO Non-Reset Pin States


#1

I am using the Q2687G, and the documentation is pretty clear about the reset state of the GPIO pins, but I have found nothing after hour upon hour of searching about what the pin drive mode is when you change it from the reset state. Here’s an example:

GPIO24
pin: 58
I/O Type: 2V8
Reset State: Z (high impedance)

So what happens if I do an ioSubscribe and set it as an output? Is it a strong drive when high or low? Some of the GPIOs have a reset state of pull-up or pull-down. What happens if I switch those to an output? Do they still have the same drive, just a different direction? If that’s the case, how about the pins with an undefined reset state? Hopefully I have described my question clearly enough. Thank you in advance for any help.

Peter


#2

if you set your output to ‘1’ or to ‘0’ the processor will try to make the voltage on the pin the high/low voltages associated with that pin.

what those voltages are, and how much current they can maximally sink/source varies per pin and can be found in the Product Technical Specification of your product.

(look for Electrical specs for digital IO in the PTS)
for example. the GPIO24 (on an Q2686) will get to:
VOH: min. 2.4v
VOL: max 0.4v
IOH: 4mA
IOL: 4mA