SerDes
Beginner
The special circuits that send data very fast between separate chips over a few wires.
Novice
Serializer/deserializer: a transmitter turns wide, slow parallel data into a fast serial stream on one wire pair, and a receiver turns it back. Used for chip-to-chip links.
Expert
Long-reach links with equalization and clock recovery, costing several pJ/bit and significant edge area; short on-wafer or on-interposer parallel links avoid most of that cost.
Explained in Wafer-scale and SRAM-heavy designs (Architectures).