Processor system and control method thereof

摘要

A processor system according to the present invention includes a storage unit, a control information area that stores an access prohibit flag capable of switching from an allow side to a prohibit side, a main PEa that issues an access request to the storage unit and a request for rewriting a copy register, a security PE that evaluates whether or not the request for rewriting the copy register is valid, the copy register that stores, when the access prohibit flag is set to the allow side, a value corresponding to the allowance and, when the access prohibit flag is set to the prohibit side, a value corresponding to an evaluation result by the security PE, and an access control circuit that controls whether or not to allow access from the main PEa to the storage unit based on an output value from the copy register.

主权项

1. A processor system comprising:
a first storage unit that is composed of a plurality of electrically rewritable non-volatile memory cells; a second storage unit that stores an access prohibit flag, the access prohibit flag being capable of SW itching value from a first value to a second value; a first processor that issues an access request to the first storage unit and authentication information corresponding to the access request; a second processor that evaluates whether or not the authentication information issued from the first processor is valid; a copy register that stores a value corresponding to the first value when a value of the access prohibit flag is the first value and stores a value corresponding to an evaluation result by the second processor when the value of the access prohibit flag is the second value; and an access control circuit that controls whether or not to allow access from the first processor to the first storage unit based on the value stored to the copy register.