The Future of Semiconductors: Chiplets and Super NoCs

The world of semiconductor implementation technology is on the brink of a major transformation. The advent of chiplets, multiple silicon dice mounted on a common substrate, is gaining traction among big players, with proprietary in-house implementations already in use. This shift promises to democratize chiplet technology, allowing everyone to participate in the future.  Integrated circuits (ICs), circuits formed from a collection of components implemented on a small flat piece of semiconductor material, are commonly referred to as 'silicon chips.' These can be analog, digital, or mixed-signal in nature. The terms ASIC, ASSP, and SoC often cause confusion among the uninitiated. In simple terms, an ASIC is designed by and/or used by a single company in a specific system, an ASSP is a more general-purpose device created using ASIC tools and technologies for use by multiple system design houses, and an SoC is an ASIC or ASSP that acts as an entire subsystem.  As semiconductor process technologies evolved, it became possible to squeeze more transistors into the same area and create larger chips. For instance, the Apple A16 Bionic, manufactured at the 4-nm process node, boasts over 15 billion transistors. However, we are reaching the limits of what can be achieved with current technologies. The solution lies in chiplets, multiple dice mounted on a common substrate, forming a multi-die system.  Synopsys, a leading provider of high-quality, silicon-proven IP solutions for SoC designs, has identified four primary chiplet use cases. These include mounting multiple copies of the same die onto the substrate, splitting a design into two or more chiplets due to size and yield considerations, implementing main digital device functionality at the latest process node while using proven solutions for some input/output functions, and disaggregating the device functionality into multiple heterogeneous dice, each implemented at the optimal node for its function.  However, the challenge lies in enabling chiplets to 'communicate' with each other using die-to-die (D2D) interconnect. Synopsys is partnering with Network-on-Chip (NoC) companies to develop 'Super NoCs' that offer the highest possible bandwidths with the lowest possible latency. NoCs are used to connect large IP blocks in a chip, allowing multiple packets passing between multiple IPs to be in flight at the same time.  Arteris IP, a leading provider of network-on-chip interconnect IP solutions, has developed solutions for D2D implementations, considering factors such as cache coherency, protocol layer, link layer, and physical layer.  The chiplet-based technology is still in its infancy, with research groups and industry partners working on design methodologies, communication interfaces, and tools to accelerate time to market. As the semiconductor industry continues to evolve, the future of IC design and implementation seems to be firmly rooted in chiplets and Super NoCs.