SEMICONDUCTOR DEVICE

摘要

A semiconductor device capable of arbitrarily operating a microprocessor while protecting a secure program is provided. The semiconductor device includes a memory equipped with a first program area in which an arbitrary program is stored, and a second program area in which a secure program is stored, a microprocessor which outputs an address designating an instruction in a program, and a memory protection unit which controls access to the memory based on the address outputted from the microprocessor. When the address outputted from the microprocessor by executing the program in the first program area designates a branch allowable area in the second program area, the memory protection unit permits access to the memory. When the address designates a branch prohibition area, the memory protection unit inhibits access to the memory.

主权项

1. A semiconductor device comprising:
a memory including a first program area in which an arbitrary program is stored, and a second program area in which a program whose security is to be ensured is stored; a central processing unit which outputs an address designating an instruction in a program; and a memory protection unit which controls access to the memory based on the address outputted from the central processing unit, wherein when an address outputted from the central processing unit by executing the program in the first program area designates a first area in the second program area, the memory protection unit permits access to the memory by the central processing unit, and when the address designates a second area different from the first area, the memory protection unit inhibits access to the memory by the central processing unit.