Tamper circuit based on STM32 chip

Abstract

The invention provides a tamper circuit based on an STM32 chip. The tamper circuit comprises a battery, a switch and a resistor-capacitor (RC) charge-discharge circuit, wherein the battery is respectively connected with one end of the switch and a real time clock (RTC) register in the STM32 chip and supplies power for the RTC register, the other end of the switch is connected with one end of the RC charge-discharge circuit, and the other end of the RC charge-discharge circuit is connected with a TAMPER pin of the STM32 chip. According to the tamper circuit, additional chips (ICs) are not required to be added to achieve tamper functions, the tamper time is easy to control, and the tamper circuit is high in tamper sensitivity, low in cost, good in performance and interference resistance characteristics and long in service life of the battery.

Description

【Technical field】 [0001] The invention relates to the field of electronic information, in particular to a tamper-resistant circuit based on an STM32 chip. 【Background technique】 [0002] At present, some terminal devices related to security requirements have anti-dismantle function. In order to ensure that the anti-dismantle function of the terminal device is still effective when the power is off, it is generally realized by button batteries and RTC chips. The RTC chip is a high-precision Real-time clock IC (English full name of RTC: Real Time Clock, Chinese name: real-time clock; IC Chinese name: chip), which will increase the cost of terminal equipment, and because the button battery is directly connected to the power pin of the RTC chip, only by connecting the RTC power supply The decoupling capacitor of the foot cannot accurately control the discharge time of the power supply. If the discharge time is too short, the vibration and drop will cause the power supply to be di...

AI Technical Summary

Problems solved by technology

[0002] At present, some terminal devices related to security requirements have anti-dismantle function. In order to ensure that the anti-dismantle function of the terminal device is still effective when the power is off, it is generally realized by button batteries and RTC chips. The RTC chip is a high-precision Real-time clock IC (English full name of RTC: Real Time Clock, Chinese name: real-time clock; IC Chinese name: chip), which will increase the cost of terminal equipment, and because the button battery is directly connected to the power pin of the RTC chip, only by connecting the RTC power supply The decoupling capacitor of the foot cannot accurately control the discharge time of the power supply. If the discharge time is too short, the vibration and drop will cause the power supply to be disconnected instantaneously, and the machine will easily be locked by mistake. If the discharge time is too long, the machine will not be locked. It is not easy to control, and it is easy to accidentally lock or not lock the machine

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