Patent ID: 9310862
Filing Date: 2016-04-12
CPC Classification: G06F,G09C,H04L

Claim Text:
1. A method of monitoring performance of a processor to detect tampering and place the processor in a safe operating state that prevents unauthorized access to contents of the processor, comprising: during a normal operating mode and at least one of a power up and a reset mode, comparing a measured value of an operating parameter to a predefined set of high and low limits for the measured value to identify an out of limits measured value; and if an out of limits measured value is detected during the normal operating mode, causing the processor to enter a reset mode, and if an out of limits measured value is detected during the at least one of a power up and a reset mode, retaining the processor in a reset mode; wherein comparing a measured value comprises providing a plurality of minimum and maximum input signals from a digital circuit to an analog circuit, the plurality of minimum and maximum input signals corresponding to the predefined set of high and low limits, and receiving at the digital circuit a plurality of minimum and maximum output signals from the analog circuit, the plurality of minimum and maximum output signals corresponding to results of comparisons of the operating parameter to values determined by the minimum and maximum input signals.