When system power off, how imx6 deals with MMPF0100 to store import data before shutdown?

[JunqiYu]

Hi,all.

I have one imx6q sabre sd board,with  ref design files iMX6Q-SABRE-SDB-DESIGNFILES.zip.

Now I have some questions need your help.

q1. The ref design pmic ic is MMPF0100, its pin SDWNB not connect,can I connect the pin to cpu as a intterupt req which let cpu know power is turnning off? Or just use pin INTB as a int req?

q2.Can MMPF0100 notices imx6q power off without Li battery?If can ,how?By intterupt or I2C?

If can't,Can MMPF0100 notices imx6q power off with Li battery?If can ,how?By intterupt or I2C?

q3.How to reality i.Mx6q to detect power off and store important data before cpu shutdown? 

q4.When imx6q irq 36-pmic power off will be actived?

[JunqiYu]

Thanks for kindly and rapid response.

‘

>q2.Can MMPF0100 notices imx6q power off without Li battery?If can ,how?By intterupt or I2C?

yes. Using SDWNB.

’

When board power down occurs without coin battery,Vin begin fall,how long will MMPF0100 take from detected power down(triggering the SDWNB or LOWNIVI) to entering the coin cell mode or fails to work normally due to the lack of power?Is the time long enough for i.MX6Q to store several bytes data and disable its SNVS power?

And new questions:

q4.which ocurs first，SDWNB or LOWNIVI？

q5.If MMPF0100 pin LiCELL connect a coin battery,can it support i.Mx6Q save some data then shutdown itself gracefully when board power off?

Best regards

junqiyu

[igorpadykov · Accepted solution]

Hi JunqiYu

>q1. The ref design pmic ic is MMPF0100, its pin SDWNB not connect,can I connect the
>pin to cpu as a intterupt req which let cpu know power is turnning off?

yes

>q2.Can MMPF0100 notices imx6q power off without Li battery?If can ,how?By intterupt or I2C?

yes. Using SDWNB.

>q3.How to reality i.Mx6q to detect power off and store important data before cpu shutdown?

one can use some external power supervisor circuit, connect it to i.MX6 GPIO and use interrupt.

Best regards
igor