About state of GPIO03(126pin) at POR in Jetson Xavier NX

Autonomous Machines Jetson & Embedded Systems Jetson Xavier NX
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1

I have two questions.

(1)The GPIO03 is Low at POR in my carrier board. Thereafter the GPIO03 is set Low by software. So, I expect to be always the GPIO03=Low. But the GPIO03 has the short Hi-Z duration on Power ON or Reboot.
Why do the short Hi-z duration occur ?

(2)The GPIO03 supplies 1.4V at the Hi-Z duration in my carrier board. In this case, Are there at the risk of damage on Jetson Xavier NX?

4

Hi, the pin status during power on is fixed for its design. During power on, carrier design should NOT affect the shared IO pins status.

5

Hi, thank you for your reply.
I may have misunderstood you. sorry.
I am making modified new board based on carrier board.
I would like to ask two questions about GPIO03 again.

(1)Question1
My expectation is that GPIO03 will maintain output Low from the power-up sequence to the kernel boots.
Therefore when I refer to the document of Jetson_Xavier_NX_Pinmux_Configuration_Template_v1.06, GPIO03 is Drive0(output is low).
Therefore, I am trying to always LOW by setting push-pull output LOW in software, but there is a Hi-Z period from the power-up sequence to the kernel boot. why?
(In my experiment, when I attached an external pull-up resistor to GPIO03, there was a period of high from the power-up sequence to the kernel boot. Therefore I’m guessing there is a period when GPIO03 is Hi-Z.)

(2)Question2
On my board, voltage of 1.4V is applied to GPIO03 from the external during this Hi-Z period. In this case, Are there at the risk of damage on Jetson Xavier NX?

7

Is the period still pull-up after kernel is up?

There are lots of software stage during the whole boot process, sometimes a pin may be toggled because some driver may use it in these stages.

8

Thank you for your reply.
After kernel is up, GPIO03 is output LOW.

9

Hi,
Could you please reply my question2 ?

Question2
On my board, voltage of 1.4V is applied to GPIO03 from the external during this Hi-Z period. In this case, Are there at the risk of damage on Jetson Xavier NX?

10

Should be no risk. But why is it 1.4V? 1,4v is not a usual level.

11

Thank you for your reply.
About 1.4V, my schematic have external pull-up and pull-down resistors.
Therefore the GPIO03 are supplied resistor divider voltage.

13

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