The following table indicates which actions take place depending on power supplies and working modes:

Main power Battery backup Working mode After a tamper event…​

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image

-

-

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image

power off

  • Register the event in NVRAM

  • Activate the output

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indifferent

power off

  • Register the event

  • Activate the output

  • Power on the system and U-Boot catches the tamper event

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indifferent

suspend

  • Register the event

  • Activate the output

  • Wake up the system with an IRQ that can be processed by user space

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indifferent

running

  • Register the event

  • Activate the output

  • Trigger the tamper IRQ that can be processed by user space