W6 pin internal Pull-up setting at ECSPI Boot for i.MX6Solo

[yuuki]

Dear all,

In our system, two Flashs are connected to SS0 and SS1 of ECSPI1 port.
And ECSPI Boot from SS0 is used.

We have a problem that boot fail occurs infrequently.

W6 pin is used as ECSPI1_SS1.
This W6 pin is GPIO Input 100K pull-up by default.

We checked SS pins of ECSPI.
We found that SS1 became Low at SS0 assertion.

We think that internal Pull-up is not enabled.

Is the description of the data sheet right?

Is there the method that this pin sets to the High(Pull-up) during ECSPI Boot?

May I have advice?

Best Regards,

Yuuki

[art]

As the i.MX6Solo Data Sheet document says, actually, this pin is configured as GPIO input with 100kOhm internal pull-up enabled at out-of-reset state. Isn't there any other external load on this pin? What happens if pulling the pin up with an external resistor? Please check.

Have a great day,
Artur

[yuuki]

Dear Artur-san,

Thank you for a response.

The W6 pin is directly connected only in CS of serial Flash.
This signal line does not be pull-downed externally.

If CS of serial Flash be pull-downed internally, may it make this signal line Low?

When this line is pulled-up externally, it seems that boot fail does not occur.

Do we need outside pull-up to avoid the W6 pin becoming Low?

We cannot add outside Pull-up because development has been already completed.
Is there any good method for this situation?

May I have advice?

Best Regards,
Yuuki

[art · Accepted solution]

Q. If CS of serial Flash be pull-downed internally, may it make this signal line Low?

A. Yes.

What is the state of this signal if it is disconnected from serial flash? What value of external pull-up did you use? Please check/report.

Best Regards,

Artur

[yuuki]

Dear Artur-san,

I'm sorry.

This problem was our setting mistake.

We found W6pin having been set in Hi-z in U-Boot.

We are grateful to you for your help.

Best Regards,

Yuuki