Breaking the Chip Apart

Today, sometimes the best way to build a better computer chip is to break it into pieces.

The University of Houston presents this series about the machines that make our civilization run, and the people whose ingenuity created them. 

In 1958, engineer Jack Kilby demonstrated an important idea: several electronic parts could be made together on a single piece of semiconductor material.  The integrated circuit was born.

For decades, engineers followed that basic idea. Put more parts onto the same piece of silicon. Make the parts smaller. Pack them closer together.  The results were remarkable. Computers that once filled rooms eventually fit on our desks and then into our pockets.

Integrated Circuit, Petr Kratochvil, PublicDomainPictures.net, CC0 Public Domain. 

But putting everything onto one piece of silicon also creates problems.  A modern system-on-chip can contain many different kinds of circuits. Some perform calculations. Others handle memory, input and output, or communication. Making such a complex device as one large piece can increase the cost and difficulty of designing it.

Now engineers are exploring an idea that seems to run backward.  Instead of putting everything on one piece of silicon, they can break a complex design into smaller pieces called chiplets.

By Mister rf - Own work, CC BY-SA 4.0

A chiplet is a small integrated circuit designed to perform part of a larger job. Several chiplets can then be placed together inside one package and connected to form a complete system.

The idea is a little like building with blocks.  One block might perform calculations. Another might handle communication. Different blocks can even be made using different technologies before being brought together.

The DARPA CHIPS program explored this modular approach. Its goal was an ecosystem of reusable circuit blocks that could be assembled into systems. DARPA noted that this kind of modular design requires electrical and physical standards so the pieces can work together. 

And that raises an interesting problem.  Splitting a chip into pieces is useful only if the pieces can communicate.  An industry specification called Universal Chiplet Interconnect Express, or UCIe, provides a common way for dies to communicate within a package. The UCIe specifications cover physical connections, communication protocols, and other parts of die-to-die communication. 

So perhaps we're seeing another turn in an old engineering story.  First, engineers built electronic systems from many separate parts.  Then they learned to combine those parts onto a single chip.  Now they are taking some very complicated chips and dividing them again.  But we've not simply returned to where we started. These smaller pieces can still sit together inside one package and act as parts of a larger system.

Engineering often works that way. We combine things, divide them, and combine them again.  The important question isn't whether a machine has more pieces or fewer.  It's whether we've found the right pieces and connected them in a way which allows each to do its specialized job at peak efficiency.

I’m Andy Moon, at the University of Houston, where we’re interested in the way inventive minds work.

(Theme music)

References

1. DARPA: Common Heterogeneous Integration and IP Reuse Strategies (CHIPS) describes the program's vision of discrete, modular and reusable IP blocks assembled into systems, as well as the need for interface standards.
   Read the DARPA CHIPS program page [darpa.mil]
2. UCIe Consortium: Specifications describes UCIe as an open industry standard for package-level interconnection covering physical, protocol and software layers, intended to support chiplet-based systems.
   Read the UCIe specifications overview [uciexpress.org]
3. Georgia Tech: Common Heterogeneous Integration and IP Reuse Strategies describes dividing an electronic system into functional circuit blocks, or chiplets, and integrating them rather than following a monolithic design process.
   Read the Georgia Tech CHIPS overview [sites.gatech.edu]
4. Cadence: Learn All About UCIe describes UCIe as an open industry standard for die-to-die communication between chiplets, including its physical, link and protocol layers.
   Read the Cadence UCIe overview [cadence.com]

This episode first aired November 11, 2026.