Encrypted Test Mode Control Circuit for Secure Mounting Tests
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing semiconductor manufacturing processes face risks of confidential information exposure and code abuse due to unprotected test mode codes being provided to buyers, compromising the security of the manufacturing process.
Innovation Solution
A test mode control circuit incorporating a non-volatile memory, encrypting circuit, and test mode generating circuit to encrypt and manage access codes, ensuring secure test mode entry and operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If test mode codes are provided to buyers without protection, then buyers can perform mounting tests on semiconductor apparatus, but confidential information of manufacturer becomes open to public and codes become abused
Solution Approach 1:
The patent introduces an encrypting circuit as an intermediary component between the test mode control logic and the external interface. This encrypting circuit transforms the original access codes into encrypted forms using encryption keys stored in non-volatile memory. The mounting test can still be performed by providing encrypted codes to buyers, while the confidential information remains protected because the encryption process acts as a mediator that hides the original code structure and values from external observation.
2Reliability
If access codes are encrypted using non-volatile memory and encrypting circuit, then security of test mode codes is enhanced, but device complexity increases
Solution Approach 1:
The patent segments the test mode control functionality into distinct modular components: (1) non-volatile memory units for storing encryption keys, (2) encrypting circuit blocks for code transformation, and (3) test mode control logic for generating test signals. This segmentation allows the encryption functionality to be added as separate modules rather than integrating complexity throughout the entire system, making the increased complexity more manageable and localized to specific security-related components.
Data Source
AI summary
A test mode control circuit includes an encryption circuit and a test mode generating circuit. The encryption circuit encrypts, based on an encryption code, an access code set to generate an encrypted access code set. The test mode generating circuit generates a test mode signal based on the encrypted access code set.