UCIe-A Mimic Channel Design and Verification for Early on-Chip System Validation

This paper presents a low-cost on-chip mimic channel that replicates the electrical behavior of a 2.5D UCIe-A interposer using multi-layer grounded coplanar waveguide (GCPW) routing. The proposed design achieves an insertion loss of -4.75 dB and crosstalk of -36 dB at 16 GHz, both compliant with UCIe-A specifications. Time-domain simulations at $32 \text{Gb} / \mathrm{s}$ with a target BER of $1 \mathrm{e}-15$ confirm adequate eye margin, validating the mimic channel's signal integrity. This architecture enables early-stage UCIe-A module validation on a single test chip without the cost and complexity of interposer-based packaging. The proposed methodology is broadly applicable to other highspeed chiplet interfaces, providing a scalable and cost-effective framework for early-stage interconnect design, evaluation, and prototyping.