UCIe

UCIe, short for Universal Chiplet Interconnect Express, is an open standard intended to connect chiplets—small integrated circuit blocks—from different vendors into a single package or multi-die system. It is designed to enable modular, heterogeneous integration by providing a common, interoperable interconnect for compute, memory, and other functions across chips assembled in a single device.

The standard defines a layered architecture that includes a physical layer for high-speed differential signaling, a link layer, a transaction or protocol layer, and a software interface. It supports scalable bandwidth, low latency, and flexible topology, including point-to-point and more complex fabrics that may incorporate switches or routers. UCIe is designed to accommodate on-package, interposer-based, or motherboard-based implementations, aligning with various packaging technologies used in high-performance computing and data center systems.

A key aim of UCIe is to enable interoperability among chiplets from different vendors, reducing integration costs and accelerating time-to-market for heterogeneous platforms. The protocol addresses data transfer, addressing, and control flows, and it includes considerations for reliability, error handling, and quality of service. Where implemented, it can support coherent memory models and shared memory semantics to facilitate seamless memory access across chiplets.

Governance and status: UCIe is developed under an industry consortium that promotes an open, royalty-free standard intended to foster ecosystem growth. Specifications are released publicly to encourage broad adoption by semiconductor vendors, IP providers, and system integrators. UCIe is positioned as a key enabler for scalable chiplet-based architectures and 2.5D/3D integration in modern computing platforms.