Microprocessor with single pin for memory wipe
AssigneeDallas Semiconducter Corp.
InventorsStephen N. Grider, Wendell L. Little, Michael L. Bolan
Life of this patent
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Abstract
A nonvolatile microcontroller (or microprocessor) with improved security against tampering, including attempts at active intrusion. According to this invention, a battery-backed microcontroller includes encryption and power management functions, and is combined with a battery and a volatile semiconductor memory (e.g. an SRAM). The microcontroller supplies power to the semiconductor memory (either from a system power supply or from the battery). When a security violation is detected, the microcontroller wipes its encryption registers, and also grounds the power-output pin to the memory. This will destroy all data in the volatile memory.
Claims14
A nonvolatile microprocessor-controlled module, comprising:
- encryption circuitry, said encryption circuitry including encryption registers;
- power management circuitry having power input nodes;
- a battery, said power input nodes coupled to said battery and to an external power supply terminal;
- a volatile memory;
- security violation detectors to detect a security violation;
- a microcontroller coupled to supply power via said power management circuitry to said volatile memory and to control said encryption registers, said security violation detectors coupled to said microcontroller;
- and wherein when a security violation is detected by said security violation detectors, said security violation detectors rewrite said encryption registers to a known value.
Dependencies are inferred from the claim text.