Silicon Labs Cp, Inc.

Cygnal Integrated Products, Inc.

Ken Fernald

Method and apparatus for protecting internal memory from external access. A method for protecting a memory space from external access is provided. A plurality of lock bits are stored in a location in memory, each associated with a separate logical portion of the memory space and determinative as to the access thereof for a predetermined operation thereon. a request is then detected for access to a location in the memory space for operating thereon. The requested operation is then compared with the associated lock bit in the associated logical portion and then it is determined if access is allowed for the requested operation. If allowed, the requested operation is performed.

Method and apparatus for protecting internal memory from external access

An embedded microprocessor two level security system in flash memory. The memory includes an address input and a memory space of addressable locations having a restricted area and a user area. Addressing one of a the addressable locations therein results in the output of information therefrom in response to the receipt of an associated address on the address input. A logic device is provided for determining if a received address on the address input corresponds to an attempt to access an addressable location in the restricted space for output of information therefrom as the result of execution of a program instruction from the user area by an external processor. An inhibit device is provided for inhibiting access to the addressable location if a positive determination is made by the logic device

Growing community of inventors

Austin, TX, United States of America

Ken Fernald