Question, i.MX25 A2 pin status

[Aemj]

Dear team,

I would like to ask about a pin status of i.MX25 right after reset.

On my customer’s board, the A2 port is used as GPIO after their software configures its IOMUX. And Pull-Up register is connected to A2 pin of i.MX25. They saw about 1.0V of voltage is seen on A2 pin after reset before software configuration.

According i.MX25 datasheet, The port status of A2(A10,ALT5:GPIO4-0) pin of i.MX25 seems to be OUTPUT/Low.

So, can I understand as below?

Before IOMUX configuration the A2 pin is set to EIM_DA_H[10].

And if the external pull-up register is connected, the voltage will be the divided voltage by the pull-up and internal register value.

Am I correct?

Thanks,

Miyamoto

[art]

What do you mean as the "number of the internal register"?

Artur

[Aemj]

Hi Artur,

The value of the internal resistance of A2 pin when i.MX25 start-up before IOMUX configuration.

Does it make sense?

Miyamoto

[art]

After reset and before software configuration, the pin is configured as input with keeper circuit enabled. The interaction of a keeper circuit with an external pull-up resistor can cause any unpredictable state of the pin before it is clearly configured.

Artur

[art]

Yes, your understanding is correct.

Have a great day,
Artur

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[Aemj]

Hi Artur,

Sorry for my late reply.

Can I have the number of the internal register?

BR,

Miyamoto

[Aemj]

Hi Artur,

Sorry for rushing you, but i still wait for your comment.

BR,

Miyamoto