Patent attributes
A method and apparatus for protecting access to sensitive information stored in vulnerable storage areas (e.g., public memory, registers, cache) of a microprocessor. A microprocessor having a reset port to receive external reset commands may have a reset diversion circuit that may be selectively enabled. The microprocessor may operate in an open mode or a secure mode, indicating the absence or the potential presence, respectively, of sensitive information in the vulnerable storage areas. In open mode, the reset diversion circuit may be disabled such that external reset requests triggers a hardware reset. In secure mode, sensitive information may be recorded on vulnerable storage areas. The reset diversion circuit may be enabled to divert external reset requests to an interrupt which may trigger execution of a software code. The software code, when executed, may perform a secured system clean-up routine to erase the vulnerable storage areas prior to reset.
