iMX257 : monitoring the wait mode from device outside

[koichisakagami]

Dear community,

We have been developing our product with iMX257.
We plan to use Wait Mode for low power consumption.

We would like to monitor the wait state  from device outside.

[Question]

        Is it possible to verify Wait Mode by observing an outside pin ?
        Is it possible to verify Wait Mode by observing a register  ?

        Do you have any other ideas ?

    Best Regards,
    Koichi Sakagami

[igorpadykov · Accepted solution]

Hi Koichi

according to sect.15.4.3.2.2 Wait Mode  MX25 RM:

"In wait mode, the processor clock is gated" so one can observe it

on CLKO pad using setting MCR register  CLKO SEL=0111 Gated arm_clk

Also one can set any gpio level 0 before entering low power mode (wfi instruction),

and set to 1 immediately after it (exit from low power mode).

Best regards

igor

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[koichisakagami]

Dear Igor san,

Thank you for reply.

We will try them.

Best regards,

Koichi Sakagami