Complete system power cycle detection and related methods

Abstract

A processor system may include multiple circuits that are each powered by their own power rails. Incomplete cycling of system power may fail to discharge memory circuits, leaving that data vulnerable to unauthorized access upon reboot. A processor system includes a boot detection circuit that, upon detecting a threshold voltage on a first power rail in the bootup sequence, captures voltage measurements on each of the remaining power rails in multiple time periods, wherein the captured voltage measurements may be analyzed to determine whether the voltages on the power rails fully cycled to a sufficiently low voltage and remained there for a sufficient time to ensure that memory circuits adequately discharged. The power system may proceed to generate an indication of complete reset or incomplete reset depending on the voltage measurements stored in the memory. In this way, the confidentiality of data previously stored in the memory circuits is protected.

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