External pull-up/pull-down is needed to i.MX6UL "input, keeper" pads?

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External pull-up/pull-down is needed to i.MX6UL "input, keeper" pads?

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satoshishimoda
Senior Contributor I

Hi community,

Our customer have a question about i.MX6UL pin.
Please see Table 95 in IMX6ULCEC Rev.1.
The Out of Reset Condition of many pads are "Input, value=keeper".
Our customer want to know whether external pull-up/pull-down to decide input logic, because thye think i.MX6UL will unexpected work by undifined logic if these pads are floating.
Would you let me know whether should they connect pull-up or pull-down to these pads?
Or external pull-up/pull-down is needed since internal pull-up/pull-down decide the logic?


Best Regards,
Satoshi Shimoda

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igorpadykov
NXP TechSupport
NXP TechSupport

Hi Satoshi

keeper prevents pad from floating, please look at

Bus-holder - Wikipedia, the free encyclopedia 

if guaranteed pad input value is needed, one can use external

pull resistor, for selection overriding resistor value please check

keeper value in Table 24. Single Voltage GPIO DC Parameters i.MX6UL Datasheet

http://cache.freescale.com/files/32bit/doc/data_sheet/IMX6ULCEC.pdf

Best regards
igor
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igorpadykov
NXP TechSupport
NXP TechSupport

Hi Satoshi

keeper prevents pad from floating, please look at

Bus-holder - Wikipedia, the free encyclopedia 

if guaranteed pad input value is needed, one can use external

pull resistor, for selection overriding resistor value please check

keeper value in Table 24. Single Voltage GPIO DC Parameters i.MX6UL Datasheet

http://cache.freescale.com/files/32bit/doc/data_sheet/IMX6ULCEC.pdf

Best regards
igor
-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------

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satoshishimoda
Senior Contributor I

Hi Igor,

Would you give me your comment whether my understanding is correct or not?

Best Regards,

Satoshi Shimoda

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igorpadykov
NXP TechSupport
NXP TechSupport

Hi Satoshi

yes this understanding is correct.

Best regards
igor

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satoshishimoda
Senior Contributor I

Hi Igor,

Thank you for your reply.

OK, I understood.

I appreciate your great support.

Best Regards,

Satoshi Shimoda

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satoshishimoda
Senior Contributor I

Hi igor,

Thank you for your reply.

According to your reply, I understood external pull-up/down is not mandatory, and it is depend on a system of our customer whether external pull-up/down is needed or not.

Is this correct?

Best Regards,

Satoshi Shimoda

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