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Disable internal pulldown on G#23, G#24, G#25 and G#26

Posted: Thu Jul 28, 2016 9:45 am
by smilykoch
Hi guys

Is there a way to disable the internal pull down resistor on G#23, G#24, G#25 and G#26 (LED1, LED2, LED3 & LED4) ?

I can see in the RT5350 datasheet that the pins have internal pull down, but i am not sure if there is a way to disable the pulldown, to use them as regular input GPIOs?

Cheers

Re: Disable internal pulldown on G#23, G#24, G#25 and G#26

Posted: Thu Jul 28, 2016 10:22 am
by smilykoch
Nevermind, i checked out the VoCore schematics, and saw that the pins had external pull down resistors.. Once they were removed, they behave like every other GPIO.

Re: Disable internal pulldown on G#23, G#24, G#25 and G#26

Posted: Thu Jul 28, 2016 1:48 pm
by smilykoch
Hmm.. New problem? It seems the pull down resistors are used during bootstrapping for selecting DRAM config and clk select? Is there any way to get the desired behavior of correct boot, but using the GPIOs of PHY_LED, as regular GPIO inputs?

Cheers.

Re: Disable internal pulldown on G#23, G#24, G#25 and G#26

Posted: Fri Jul 29, 2016 2:02 am
by Vonger
Pulldown/up is necessary. :) And it will not effect output signal.