AM3358-EP: GPIO Configuration

Art Mecina

Part Number: AM3358-EP
Other Parts Discussed in Thread: AM3358

Hello Guys,

Good day.

Our customer wants to know how to configure the GPIO of AM3358-EP for his use, that is connected to a Reset signal.as an input with pull-up resistor active during normal operation and to then change its configuration to an output and set it low when he want to reset the IC?

Thanks in advance!

Art

over 3 years ago

0 Andreas Dannenberg over 3 years ago

TI__Guru 50241 points

Art,

are you saying you want to control the state of the GPIO (driving it to low) during AM335x reset? If this is what you are trying to do you will need to use some external glue logic to achieve that, as the pin state can't be controlled/configured during device reset.

Regards, Andreas

0 Art Mecina over 3 years ago in reply to Andreas Dannenberg

TI__Genius 16505 points

Thanks Andreas!

I have relayed this post to the customer. It would be best if he can communicate directly to you guys.

Art

0 Andreas Dannenberg over 3 years ago in reply to Art Mecina

TI__Guru 50241 points

Hi Art,

we should try to manage communication as much as possible via E2E, this way building our knowledge base and allowing others to benefit from the information that is shared as well. This being said please let me know anything we can do to help.

Regards, Andreas

0 Art Mecina over 3 years ago in reply to Andreas Dannenberg

TI__Genius 16505 points

Hello Andreas,

I sent you a separate email regarding this to discuss offline.

Thanks!

Art

0 Art Mecina over 3 years ago in reply to Art Mecina

TI__Genius 16505 points

Hello Andreas,

Getting back on this inquiry.

Our customer is not resetting the AM335x at all and do not want to control pins during its reset. He is connecting GPIO1_20 of the AM3358 to the reset pin of another IC he have on his PCB.

This other IC has an internal pull-up on it's reset pin. Therefore, he wants GPIO1_20 to be in a high impedance state until he want to reset the other IC, then the GPIO must be set to a low state briefly before returning to high impedance.

What is the correct way to configure GPIO1_20 to be in a high impedance state?

Thanks in advance!

Art

0 Andreas Dannenberg over 3 years ago in reply to Art Mecina

TI__Guru 50241 points

Hi Art,

thanks for the clarification. If you want to do that without using any additional hardware you will need to toggle the GPIO between "input" and "output low" modes to emulate an open-drain output which is what you would want in your scenario, as the AM335x's GPIO module can't be configured for actual open-drain operation. Please find more info here: https://e2e.ti.com/support/processors/f/791/p/293683/1024016#1024016

Regards, Andreas

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AM3358-EP: GPIO Configuration