MCU Flash Memory Sub-Area Segmentation for Inter-Company Access Control
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Solution Overview
Problem
Current information protection methods for MCU chips only protect programs in the user area from being stolen by users and fail to prevent cooperative companies from stealing each other's programs, as they do not allow for separate protection and access control between multiple companies developing the program.
Innovation Solution
The MCU chip divides the user area into two sub-areas, allowing separate access and protection for each company, with a flash controller managing access states and reading protection levels based on option bytes, and utilizing sub-area enabling signals for private peripherals to control access to shared resources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the user area is protected as a whole using current information protection methods, then the program is protected from being stolen by users, but cooperative companies cannot have separate access control and can steal each other's programs
Solution Approach 1:
The flash memory is divided into multiple sub-areas (first sub-area and second sub-area) with separate access control. Each sub-area can be independently protected, allowing different companies to have exclusive access to their respective sub-areas while maintaining overall program protection. This segmentation enables both user protection and inter-company access control.
2Adaptability or versatility
If the user area is divided into multiple sub-areas for separate access control, then cooperative companies can have independent protection, but the device complexity increases
Solution Approach 1:
An access control circuit is introduced as an intermediary component to manage access to different sub-areas. This circuit receives enabling signals and controls whether the instruction bus can access specific sub-areas, thereby managing the complexity of multi-sub-area access control through a dedicated control mechanism rather than分散的控制逻辑.
3Reliability
If access control is implemented for multiple sub-areas, then cooperative companies are prevented from stealing each other's programs, but the ease of operation decreases
Solution Approach 1:
The access control system dynamically adjusts access permissions based on enabling signals. When a sub-area enabling signal is activated, the corresponding sub-area becomes accessible; when deactivated, access is prohibited. This dynamic control allows flexible management of program access while maintaining security, enabling companies to control access to their respective sub-areas as needed.
Data Source
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AI summary
The disclosure discloses a method and a device of information protection for a micro control unit (MCU) chip, the MCU chip comprises an instruction bus, a data bus, a flash controller and a user area of a flash memory; the flash controller is used to divide the user area into a first sub-area and a second sub-area; the method comprising: when the instruction bus accesses the user area, determining whether the instruction bus accesses the first sub-area; if yes, entering the first sub-area working state; in the first sub-area working state, if the instruction bus accesses the second sub-area, entering the transition state; determining whether the time at transition state reaches a preset waiting time; if yes, entering the second sub-area working state; the disclosure is used to protect program from being stolen by users and prevent the cooperative companies stealing program from each other.