Power on/off by the ONOFF button on i.MX6Q SABRE-SDP.

[satoshishimoda]

Hi community,

I have a question about i.MX6DQ ONOFF pin.

Please see chapter 10.5 in MCIMX6DQRM (Rev.3), it says about ONOFF behavior as below.

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• When the chip main power supply is Off, a button press greater in duration than 750

ms asserts an output signal to request power from a power IC to power up the SoC.

• When the chip main power supply is On, a button press between 750 ms and 5

seconds will send an interrupt to the core to request that software bring down the

SoC safely. Software may respond to the interrupt by saving the processor state and

then setting a control bit that requests to the power IC the removal of the main power

supply.

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I checked the behavior on SABRE platform (MCIMX6Q-SDP), and i.MX6 was woken up when the chip main power supply is off even if the term I pushed the power button is less than 750ms.

Also, i.MX6 enters standby mode with Android BSP when when the chip main power supply is on even if I pushed the power button less than 750ms.

What were happen?

Best Regards,

Satoshi Shimoda

[art · Accepted solution]

The 750ms off -> on transition time value, given in the Section 10.5 of the i.MX6DQ Reference Manual Rev.3 document, is incorrect, it is just a typo. Actually, the default off -> on transition time is 500ms, moreover, it can be configured in software. For more information, please refer to the Chapter 57, especially, to the Sections 57.6.1 and 57.9.10 of the same document.

Have a great day,
Artur

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