Digital signal controller secure memory partitioning

Abstract

A controller offers various security modes for protecting program code and data stored in memory and ensuring that the protection is effective during all normal operating conditions of the controller. The controller includes configuration settings that segment program memory into a boot segment, a secure segment and a general segment, each with a particular level of security including no enhanced protection. The boot code segment (BS) is the most secure and may be used to store a secure boot loader. The secure code segment (SS) is useful for storing proprietary algorithms from third parties, such as algorithms for separating ambient noise from speech in speech recognition applications. The general code segment (GS) has the least security. The controller is configured to prevent program flow changes that would result in program code stored in high security segments from being accessed by program code stored in lower security segments. In addition, the processor may be configured to have associated secure data portions of both program memory, such as flash memory, and random access memory (RAM) corresponding to the BS, SS and GS. Attempts 15 to read data from or write data to the program memory or RAM associated with a higher security level from a lower security level are prevented from occurring.

Description

Technical field

[0001] The present invention relates to a system and method for preventing code or data duplication or modification to one or more segments of a memory in a controller chip such as a microcontroller, a microprocessor, a digital signal controller or a digital signal processor, And more particularly, it relates to a system and method for prohibiting a program running in an insecure area of ​​the memory from accessing a memory segment. Background technique

[0002] Controllers such as microcontrollers, microprocessors, digital signal controllers, and digital signal processors are conventionally constructed to be programmable to execute specific applications and functions in the system. Generally speaking, these devices can be programmed by the customer without restrictions, or programmed during the manufacturing process using software provided or specified by the customer. Therefore, conventionally, the code in the controller is designed to be accessible by the clien...

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