i.MX6DQ behavior when VDDHIGH_IN is not supplied.

[satoshishimoda]

Hi community,

Our customer have a question about i.MX6DQ.

Would you let me know the i.MX6DQ behavior if VDDHIGH_IN is not supplied when other powers are supplied.

Toggle PMIC_ON_REQ to reset PMIC? or other action?

Actually, VGEN5 output was toggled when cut off the connection between VGEN5 and VDDHIHG_IN on thier custom board.

(Connection between MMPF0100 and i.MX6DQ is same as SABRE SDP except VGEN5)

They want to know why VGEN5 output was toggled, and I guess it caused by toggling of PMIC_ON_REQ.

Best Regards,

Satoshi Shimoda

[Yuri · Accepted solution]

Hello,

  Strictly speaking, we can observe unpredictable i.MX6 behavior, when

some power supply voltage is not applied (or when power up sequence

or voltages do not meet specs) : in particular - toggling of PMIC_ON_REQ.

Have a great day,
Yuri

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[satoshishimoda]

Dear Yuri,

You said "unpredictable i.MX6 behavior" about toggling of PMIC_ON_REQ.

So the i.MX6 behavior when some power supply voltage is not applied will be other behavior also?

The toggling of PMIC_ON_REQ is incidental?

Best Regards,

Satoshi Shimoda

[Yuri]

Hello,

PMIC_ON_REQ is controlled by the ONOFF pad, SNVS_LP DP_EN and

Power Glitch Detection bits. It can cause assertion and following negation

of PMIC_ON_REQ. 

How to de-assert PMIC_ON_REQ by software. 

Regards,

Yuri.

[satoshishimoda]

Dear Yuri,

Thank you for your reply, and sorry for delay.

>PMIC_ON_REQ is controlled by the ONOFF pad, SNVS_LP DP_EN and

> Power Glitch Detection bits.

I think ONOFF = high, and Power Glitch Detection bits is disabled when power-up.

So the PMIC_ON_REQ assertion by VDDHIGH_IN lacking is not controlled behavior by SNVS, right?

Best Regards,

Satoshi Shimoda

[Yuri]

Hello,

   Is it possible to look at PMIC_ON_REQ  waveforms ;

what does it mean - toggling ?

Regards,

Yuri.