Component Die VBIST Engine for Independent Early Validation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In multi-chip modules (MCMs), the validation, testing, or debugging of subsidiary dies is delayed until the main compute die becomes available in silicon, leading to wasted time and resources, as these dies cannot be validated independently.
Innovation Solution
Incorporating a validation built-in self-test (VBIST) engine within each subsidiary die that enables independent validation and testing by generating test data streams, receiving responses, and validating them, even in the absence of the main die, using a configurable switching matrix for various testing modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If subsidiary dies are validated only after the main die is available, then validation can be performed with complete system context, but development time is extended and resources are wasted
Solution Approach 1:
The patent implements preliminary validation by incorporating a VBIST engine within each subsidiary die that enables independent validation before the main die is available. The VBIST circuit generates test data streams, routes them through component circuitry and interface circuitry, and validates responses using a tracker, allowing early defect identification without requiring the complete system context of the main die.
2Productivity
If independent validation of subsidiary dies is enabled, then development time is reduced, but device complexity increases due to additional VBIST circuitry
Solution Approach 1:
The VBIST engine is designed as a multi-functional circuit that performs multiple validation tasks. The configurable switching matrix can route test data streams to different destinations (component circuitry, interface circuitry, or tracker directly), and the same hardware infrastructure supports various testing modes including self-test, loopback test, and validation of different circuit blocks within the subsidiary die.
3Measurement precision
If comprehensive test coverage is implemented across all component dies, then defect detection improves, but resource utilization increases
Solution Approach 1:
The VBIST engine implements self-service validation where each subsidiary die validates itself independently without requiring external testing equipment or complete system assembly. The embedded tracker validates responses from the die's own component circuitry and interface circuitry, eliminating the need for extensive external testing resources while maintaining comprehensive defect detection coverage.
Data Source
AI summary
A component die validation built-in self-test (VBIST) engine is presented. In an aspect, a component die includes component circuitry for performing a component function, interface circuitry for communicating with another die, and a VBIST circuit. The VBIST circuit includes a traffic generator that generates test data streams, a tracker that receives and validates test data streams, and a configurable switching matrix for coupling the traffic generator to at least one of the component circuitry, the interface circuitry, or the tracker, and for coupling at least one of the component circuitry, the interface circuitry, or the traffic generator to the tracker. The VBIST circuit can send traffic to and from the component circuitry directly, or indirectly via the interface circuitry in loopback mode, and can be used for memory initialization and test.