i.mx7 GPIO open-drain mux?

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i.mx7 GPIO open-drain mux?

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tmeyer
Contributor III

Hi,

I've been working with the i.mx7 processor for a few years and have always worked around the fact the the GPIO mux doesn't include a ODE bit to enable the gpio as a open-drain output. Does this part just not have a GPIO open-drain  output function? I find it hard to believe and am assuming i am just not looking in the correct place in the reference manuals.

Can someone confirm how to enable ODE for the GPIO, if even possible?

Thanks.

Tim

The typical pad control register looks like this (from the mx7S/D RM):

pastedImage_1.png

Where from the i.mx6, for example, they pad control looks as follows:

pastedImage_2.png

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weidong_sun
NXP TechSupport
NXP TechSupport

Hello Tim,

 

   Yes, i.mx7D pads couldn't be set Open Drain IO mode.

   If you really need OD IO, you can do like this:

(1) external pull up to high via a resistor on a PAD

(2) Setting the GPIO to be INPUT MODE

the pin will OUTPUT 1

(3) Setting the GPIO to OUPUT mode

Set the GPIO to ouput 0.

That is to say,  Open Drain mode is realized by changing IO direction of GPIO.

Have a nice day!

Best Regards,

weidong

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weidong_sun
NXP TechSupport
NXP TechSupport

Hello Tim,

 

   Yes, i.mx7D pads couldn't be set Open Drain IO mode.

   If you really need OD IO, you can do like this:

(1) external pull up to high via a resistor on a PAD

(2) Setting the GPIO to be INPUT MODE

the pin will OUTPUT 1

(3) Setting the GPIO to OUPUT mode

Set the GPIO to ouput 0.

That is to say,  Open Drain mode is realized by changing IO direction of GPIO.

Have a nice day!

Best Regards,

weidong

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