Data processing circuit and communication mobile terminal device

Abstract

The invention provides a data process circuit and a communication mobile terminal device, which is capable of inhibiting illegal access to internal data of a microprocessor when performance of the microprocessor is deteriorated caused by separating from specific working conditions within a working guarantee range. A first detector (152) that detects whether the operation of the data process circuit with a controller (147) deviates from a first operating condition and a second detector (154) that detects whether the operation of the data process circuit deviates from a second operating condition which is stricter than the first one are employed; when the first detector detects deviation from the first operating condition, reset is instructed to the controller; the controller (147) may rewrite a rewritable nonvolatile memory (146) and control the nonvolatile memory as well as external interface; when the second detector detects deviation from the second operating condition, the controller backs up an internal state and imposes a restriction on external access to a storage region of the nonvolatile memory.

Description

technical field [0001] The present invention relates to a data processing circuit with a microcontroller, such as an IC card or a Subscriber Identity Module (SIM) card, and in particular to a technology effectively applied to a communication mobile terminal device equipped with a Subscriber Identity Module card. Background technique [0002] A data processing circuit represented by an IC card has tamper-resistant properties as a defense against internal analysis (reverse engineering) and alteration. For example, as anti-tampering, a microcontroller applied to an IC card (microcontroller for an IC card) is equipped with a temperature value, voltage, value, or the detection circuit of the operating frequency value to protect important data stored in the memory within the microcontroller from external attacks such as current analysis and physical analysis. When the detection circuit detects a temperature value, voltage value, or operating frequency value outside the specified ...

AI Technical Summary

Problems solved by technology

The technology of Patent Document 3 prevents the degradation of the characteristics of the memory itself, but does not combine the degradation of the characteristics of the memory with the suppression of illegal access

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