Accelerating UCIe Multi-die Verification with a Scalable, Smart Framework

In the rapidly evolving landscape of semiconductor design, multi-die systems are revolutionizing performance and scalability, making them indispensable for modern applications. By distributing functionality across interconnected dies, they offer several advantages, such as scalability, which allows for easier integration of more functionality and better performance than monolithic designs. Additionally, different dies can specialize in specific tasks, optimizing workloads like high-speed computing and AI, and reducing reliance on larger, expensive
single-die solutions enables the creation of tailored product variants.

The Universal Chiplet Interconnect Express (UCIe) protocol has emerged as a pivotal framework for facilitating communication in these multi-die systems. As the need for higher performance and flexibility in chip design grows, UCIe provides a standardized approach to interconnect multiple dies, enabling efficient data transfer and enhanced functionality. By supporting diverse chiplet designs, UCIe promotes scalability and specialization, allowing different dies to optimize tasks like processing and data management.

However, transitioning to multi-die systems and implementing UCIe complicates verification. Key challenges include inter-die communication, which involves testing interactions between dies and managing timing, error correction, and data integrity across protocols. Synchronization and timing present another difficulty, as ensuring all dies operate in sync despite varying processing delays is challenging. Furthermore, cross-protocol verification adds complexity, as multiple protocols (PCIe, CXL, UCIe) must be integrated and verified, creating
a more intricate landscape compared to single-die systems.

UCIe 2.0 introduces additional complexities in verification with new requirements and features. The Management Transport Protocol in UCIe 2.0 multiplexes management and sideband traffic, necessitating careful verification to avoid interference with data traffic. Advanced features like lane repair and autonomous link training must also be rigorously tested to ensure system reliability. These challenges underscore the need for comprehensive verification to achieve robust performance and reliability in multi-die architectures that leverage the UCIe protocol.

Verification Challenges in Multi-die System

Multi-die systems, while providing significant benefits in performance, scalability, and flexibility, introduce unique verification challenges. These challenges arise from the complexity of integrating multiple dies, evolving protocols, and ensuring that different system components interact seamlessly at
both the block and system levels.

Transition from block-level to system-level verification

Multi-die systems demand a shift from traditional block-level validation, where individual components are tested in isolation, to system-level verification, where the interactions between all dies and their components must be considered.

1. Inter-die communication: Data and control signals travel between dies via complex interfaces, making it crucial to validate the integrity of these communications.
2. System-wide functionality: Beyond verifying that individual blocks function correctly, it’s essential to ensure that these components work together across the entire system, addressing synchronization issues, timing variations, and protocol interoperability.

This transition complicates testbench creation, as block-level verification methodologies often lack the capability to validate system-wide interactions, requiring a new approach to system-level testing.