AnsweredAssumed Answered

imx28 power off with USB connected

Question asked by Dragan Sarbut on Jan 23, 2013
Latest reply on Jan 23, 2013 by Yuri Muhin

Hi,

I have the following scenario:

imx28 is connected to a battery and to a 5V USB power supply.

Powering off the chip via the HW_POWER_RESET_PWD bit causes the device to automatically restart if the USB power supply is still present.

 

I do not have the possibility to disable the 5V USB supply from software and I do not want to blow the DISABLE_RECOVERY_MODE OTP bit because at some point we may need recovery mode.

 

Question: how would you prevent the chip to boot if USB 5V is present?

I tried waiting for PSWITCH in XLDR if the start-up source is the 5V and only resume boot if PSWITCH LSB is high but this consumes about 10 mA from the battery and this is too much.

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