Method for protecting memory against unauthorized access
AssigneeTexas Instruments Incorporated
InventorJohann ZIPPERER
Life of this patent
Estimating the term…
Abstract
A method of protecting software for embedded applications against unauthorized access is disclosed. Software to be protected is loaded into a protected memory area and access to the protected memory area is controlled by sentinel logic circuitry. The sentinel logic circuitry allows access to the protected memory area only either from within the protected memory area or from outside of the protected memory area but through a dedicated memory location within the protected memory area. The dedicated memory location then points to protected address locations within the protected memory area.
Claims17
An electronic device comprising:
- a memory having a protected area, a non-protected area, and an auxiliary area separate from the protected area and the non-protected area;
- and
- access control circuitry to protect the memory against unauthorized access by:
- permitting access to the protected area for read, write, or execution operations in response to first instructions stored in the protected area;
- permitting access to a dedicated area within the protected area for read, write, or execution operations in response to second instructions stored in the non-protected area;
- prohibiting access to any memory location of the protected area other than the dedicated memory location for read, write or execution operations in response to the second instructions;
- and
- permitting access to the auxiliary area for read or write operations in response to third instructions stored in the protected area.
An electronic device comprising:
- a memory including a first non-protected area having a first address range, a second non-protected area having a second address range, a first protected area having a third address range, and a second protected area having a fourth address range;
- and
- access control circuitry to protect the memory against unauthorized access by:
- permitting access to the second protected area for read, write, or execution operations in response to first instructions stored in the first protected area;
- permitting access to the first protected area read, write, or execution operations in response to second instructions stored in the first non-protected area;
- and
- prohibiting access to the second protected area for read, write or execution in response to the second instructions.
Dependencies are inferred from the claim text.