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iMX6 Quad doesn't boot after External Reset

Question asked by Tamilarasan E on Jun 25, 2015
Latest reply on Jun 26, 2015 by igorpadykov

In Imx6 Quad , after pressing RESET switch SOM doesn't boot again. it boots only after hard power on/off.

As per my understanding, through external reset released, internal Reset will release only after  VDD_ARM_CAP and VDD_SOC_CAP supplies
are stable (internal  LDO_CORE and LDO_SOC).

so , i doubt these internal voltage domains and their input voltages  VCC_SW1AB_CORE and VCC_SW1C_SOC of PMIC (MMPF0100F0AEP)

Findings:

1. in Linux, boots  after reset  switch is pressed with out problem and  VCC_SW1AB_CORE and VCC_SW1C_SOC voltages of  PMIC are fine. ( no voltage dip occurs-here current consumption from  VCC_SW1AB_CORE is  < 500mA)

2. In android
         1. if reset switch is pressed at the time of uboot, and kernel loading , booting occurs without problem ( up to this process current consumption form VCC_SW1AB_CORE is  < 700mA )
         2. once android application launches , current consumption from VCC_SW1AB_CORE is increased >900mA, and voltages dip occurs ( snap shot attached) if reset switch is pressed now,  doesn't boot again.


3. first dip occurs from 1.35 to 1.28V at that time current is around 700mA.  if i press reset switch here, boot occurs without problem

tek00012.bmp

 

 



4. After some time (  launching android application) continuous dip occurs  from ( 1.28V to 0.992V) here current is around 900mA  . if i reset here, board doesn't boot . and
VCC_SW1AB_CORE is in 0.992V itself.
tek00011.bmp
Green -VCC_SW1AB_CORE of PMIC
Blue-
VCC_SW1C_SOC of PMIC

 

Same issues occurs in 3 boards.

 

Is anyone faced this issue...? Pls let me know the solution for this.?

 

Thanks

Tamilarasan.

 

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