Method and apparatus for limiting access to an integrated circuit (IC)
First Claim
1. An integrated circuit (IC) comprising:
- a voltage detector for detecting tampering with a power supply voltage of the IC; and
a temperature detector for detecting tampering with a temperature of the IC, wherein a combined average power consumption of the voltage detector and the temperature detector is less than five microwatts.
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Accused Products
Abstract
A method and apparatus for limiting access to an integrated circuit (IC) upon detection of abnormal conditions is provided. At least one of abnormal voltage detection, abnormal temperature detection, and abnormal clock detection are provided with low power consumption. Both abnormally low and abnormally high parameter values (e.g. abnormally low or high voltage, temperature, or clock frequency) may be detected. Abnormal clock detection may also detect a stopped clock signal, including a clock signal stopped at a low logic level or at a high logic level. Furthermore, abnormal clock detection may detect an abnormal duty cycle of a clock signal. A sampled bandgap reference may be used to provide accurate voltage and current references while consuming a minimal amount of power. Upon detection of an abnormal parameter value, one or more tamper indications may be provided to initiate tampering countermeasures, such as limiting access to the IC.
37 Citations
20 Claims
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1. An integrated circuit (IC) comprising:
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a voltage detector for detecting tampering with a power supply voltage of the IC; and a temperature detector for detecting tampering with a temperature of the IC, wherein a combined average power consumption of the voltage detector and the temperature detector is less than five microwatts. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method, at an integrated circuit (IC), comprising:
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detecting, using a voltage detector of the IC, tampering with a power supply voltage of the IC; and detecting, using a temperature detector of the IC, tampering with a temperature of the IC, wherein a combined average power consumption of the voltage detector and the temperature detector is less than five microwatts. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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17. An integrated circuit (IC) comprising:
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a voltage detector for detecting tampering with a power supply voltage of the IC; a temperature detector for detecting tampering with a temperature of the IC, wherein a combined average power consumption of the voltage detector and the temperature detector is less than five microwatts; and a tamper detector controller, the tamper detector controller coupled to the voltage detector and to the temperature detector, the tamper detector controller for limiting access to the IC in response to detection of tampering, wherein limiting the access comprises at least one of;
inhibiting an external signal line of the IC, inhibiting execution of an instruction in the IC, resetting at least a portion of the IC, disabling reading of at least a portion of a memory array of the IC, and disabling execution of instructions stored in at least a portion of the memory array of the IC. - View Dependent Claims (18, 19, 20)
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Specification