UCIe tutorials & labs.
The most complete UCIe curriculum on the internet — starting from the chiplet-revolution context (Moore's-Law slowdown, reticle limits, yield, cost) before touching any UCIe layer, then through chiplet architecture, the three-layer UCIe stack (Protocol / Adapter / PHY), advanced packaging (organic / silicon interposer / EMIB / 2.5D / 3D), link initialisation and training, the Streaming protocol, PCIe-over-UCIe, CXL-over-UCIe, flow control, reliability, performance, coherency, memory and AI systems, RTL design, verification, debugging, real-product case studies (AMD EPYC, Intel Meteor Lake, AI accelerators), and the chiplet-marketplace future.
Tutorials
Learn UCIe from beginner to advanced through structured tutorials.
Labs
Practice UCIe using progressively challenging hands-on labs.
What UCIe is
UCIe — Universal Chiplet Interconnect Express — is an open specification for connecting chiplets inside a package. Rather than building one large monolithic die, a system is assembled from several smaller dies, and UCIe defines how they talk: a physical layer for the die-to-die wires, a die-to-die adapter that handles link management and reliability, and a protocol layer that carries higher-level traffic across the link. Because the dies sit in the same package, the link is short, wide and comparatively low power — but it also has to be trained, monitored and repaired like any other link.
Why it exists
Large dies are expensive: yield falls as area grows, and not every function benefits from the newest process node. Splitting a design into chiplets lets each part use an appropriate process and improves yield, but only if there is a standard way for dies from different sources to interoperate. UCIe exists to make that assembly practical — a common electrical, link and protocol framework so chiplets can be mixed rather than co-designed from scratch every time.
The part engineers get wrong
Chiplet design moves part of the system boundary into the package, and that changes what counts as an architectural concern. On a monolithic die, an interconnect wire is essentially free and always works; across a die-to-die link it must be trained, its health monitored, and faults tolerated or repaired. Link bring-up, retry behaviour, sideband management and package topology stop being implementation details and become things a system architect reasons about. It is also worth being precise about what UCIe is: a die-to-die transport framework that can carry different higher-level protocols depending on the mode and profile in use — not simply PCIe relocated inside a package.
Before you start
- Digital logic and clocked interfaces
- Familiarity with a layered link protocol — PCIe is the most useful background
- Helpful: basic awareness of packaging and signal integrity concepts
What you will be able to do
- Describe what each layer of the UCIe stack contributes
- Explain how a die-to-die link is discovered and brought up
- Reason about retry and reliability across an in-package link
- Explain the role of the die-to-die adapter between protocol and physical layers
- Discuss how packaging choices affect what a die-to-die link can achieve
The learning path
- Why chipletsYield, process choice, and the case for disaggregation
- Protocol stackPhysical layer, die-to-die adapter and protocol layer
- Link structureLanes, modules and how a link is organised
- Link bring-upDiscovery and training before traffic can flow
- Adapter behaviourLink management sitting between protocol and wires
- ReliabilityRetry and error handling across the package
- PackagingStandard, 2.5D and 3D integration and their constraints
Core concepts
New to UCIe? Work through the curriculum in order — each lesson assumes the one before it, and the sequence is what turns the roadmap above into working knowledge.
Already working with it? Use the core-concept links above to jump straight to the topic you need; each one opens the lesson that covers it in most depth.
Where this leads
Standards: UCIe Consortium — The body that publishes the UCIe specification