topic Want to keep low level under POR state in i.MX Processors

Want to keep low level under POR state

ko-hey — Mon, 21 May 2018 01:00:06 GMT

Hi all

I want to keep low level under POR for GPIO pin in i.MX6SoloX.

Because if the level change, it affect other external devices.

When power is supplied to NVCC_xxx with POR applied ("0") at power on, GPIO goes to "1" even if it is externally pulled down.

I'm testing with GPIO1_IO09[A19].

When I powered on the board, the pin keep low level under POR.

After that , power is supplied to NVCC_GPIO, the GPIO1_IO09[A19] pin goes to high level despite pins pulled down externally.

Can I keep low level under POR for GPIO pin ?

Ko-hey

Re: Want to keep low level under POR state

igorpadykov — Mon, 21 May 2018 09:37:54 GMT

Hi Ko-hey

please refer to i.MX6SX Datasheet p.131
https://www.nxp.com/docs/en/data-sheet/IMX6SXCEC.pdf

Best regards
igor
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Re: Want to keep low level under POR state

ko-hey — Tue, 22 May 2018 00:21:55 GMT

Hi igorpadykov

Thank you for reply.

I understand that NXP does not recommend using GPIO1_IO09 pin as a system function.

However, I have a question about the description of the value in table.

"This signal should not be used for system functions that will require it to be an input or stable output during reset.”

Could you tell me how can user set as an input and stable output which is described above ?

As I mentioned, I pulled down that pin but it goes high.

Ko-hey

Re: Want to keep low level under POR state

igorpadykov — Tue, 22 May 2018 08:42:24 GMT

Hi Ko-hey

as NXP does not recommend using this pin, no other recommendations for its usage can be provided, sorry.

Best regards
igor