Abstract
UCIe™ (Universal Chiplet Interconnect Express™) is an open specification that defines the interconnect between chiplets within a package, enabling an open chiplet ecosystem and ubiquitous interconnect at the package level. The UCIe specification covers the die-to-die I/O physical layer, die-to-die protocols, and software stack, which leverage the well-established PCI Express® (PCIe®) and Compute Express Link® (CXL®) industry standards.