Multi-Die and Chiplet Design Methodology is the EDA and architectural approach to designing systems composed of multiple smaller silicon dies (chiplets) connected through advanced packaging rather than a single monolithic die — enabling the combination of different process nodes, IP blocks from different vendors, and die sizes optimized for yield, where the design methodology requires new tools for die-to-die interface design, system-level floorplanning, cross-die timing closure, and thermal/power co-analysis that traditional single-die EDA flows do not provide.

Why Multi-Die/Chiplet

• Monolithic die: Larger die → exponentially lower yield → cost explodes above ~400mm².
• Chiplet: Four 100mm² dies at 90% yield each = 65% system yield vs. 400mm² at ~30% yield.
• Heterogeneous nodes: CPU on 3nm, I/O on 12nm, memory on dedicated → each optimized.
• Mix and match: Reuse proven chiplets across products → reduce design effort.
• Examples: AMD EPYC (CCD + IOD), Intel Meteor Lake (compute + SOC + GFX tiles), Apple M-series.

Multi-Die Design Flow

<svg viewBox="0 0 662 321" xmlns="http://www.w3.org/2000/svg" style="max-width:100%;height:auto" role="img"><rect x="0" y="0" width="662" height="321" rx="12" fill="#0d1117"/><g font-family="ui-monospace,SFMono-Regular,Menlo,Consolas,&quot;Liberation Mono&quot;,monospace" font-size="14"><text xml:space="preserve" x="20" y="31.7"><tspan fill="#c9d1d9">1. System Architecture</tspan></text><text xml:space="preserve" x="20" y="50.7"><tspan fill="#c9d1d9">   </tspan><tspan fill="#6e7681">├──</tspan><tspan fill="#c9d1d9"> Partition into chiplets (compute, I/O, memory, etc.)</tspan></text><text xml:space="preserve" x="20" y="69.7"><tspan fill="#c9d1d9">   </tspan><tspan fill="#6e7681">├──</tspan><tspan fill="#c9d1d9"> Define die-to-die interfaces (protocol, bandwidth, latency)</tspan></text><text xml:space="preserve" x="20" y="88.7"><tspan fill="#c9d1d9">   </tspan><tspan fill="#6e7681">└──</tspan><tspan fill="#c9d1d9"> Choose packaging technology (2.5D interposer, EMIB, CoWoS, Foveros)</tspan></text><text xml:space="preserve" x="20" y="107.7"></text><text xml:space="preserve" x="20" y="126.7"><tspan fill="#c9d1d9">2. Chiplet Design (per die)</tspan></text><text xml:space="preserve" x="20" y="145.7"><tspan fill="#c9d1d9">   </tspan><tspan fill="#6e7681">├──</tspan><tspan fill="#c9d1d9"> Standard single-die RTL</tspan><tspan fill="#6e7681">→</tspan><tspan fill="#c9d1d9">GDS flow</tspan></text><text xml:space="preserve" x="20" y="164.7"><tspan fill="#c9d1d9">   </tspan><tspan fill="#6e7681">├──</tspan><tspan fill="#c9d1d9"> Die-to-die PHY (serializer, driver, ESD)</tspan></text><text xml:space="preserve" x="20" y="183.7"><tspan fill="#c9d1d9">   </tspan><tspan fill="#6e7681">└──</tspan><tspan fill="#c9d1d9"> Bump/micro-bump map matching package plan</tspan></text><text xml:space="preserve" x="20" y="202.7"></text><text xml:space="preserve" x="20" y="221.7"><tspan fill="#c9d1d9">3. System Integration</tspan></text><text xml:space="preserve" x="20" y="240.7"><tspan fill="#c9d1d9">   </tspan><tspan fill="#6e7681">├──</tspan><tspan fill="#c9d1d9"> Cross-die timing analysis</tspan></text><text xml:space="preserve" x="20" y="259.7"><tspan fill="#c9d1d9">   </tspan><tspan fill="#6e7681">├──</tspan><tspan fill="#c9d1d9"> System-level power/thermal simulation</tspan></text><text xml:space="preserve" x="20" y="278.7"><tspan fill="#c9d1d9">   </tspan><tspan fill="#6e7681">├──</tspan><tspan fill="#c9d1d9"> Package co-design (routing, RDL, interposer)</tspan></text><text xml:space="preserve" x="20" y="297.7"><tspan fill="#c9d1d9">   </tspan><tspan fill="#6e7681">└──</tspan><tspan fill="#c9d1d9"> System-level DRC/connectivity verification</tspan></text></g></svg>

Die-to-Die Interface Design

EDA Tool Challenges

System-Level Timing

• Die 1 output → D2D TX → bump → interposer → bump → D2D RX → Die 2 input.
• Total latency: ~2-10ns depending on interface (vs. ~0.1-0.5ns for on-die paths).
• Timing constraint: Must account for die-to-die latency + jitter + skew.
• Thermal variation: Each die at different temperature → different delay → cross-die OCV.

Emerging EDA Capabilities

Multi-die chiplet design methodology is the architectural paradigm that is replacing monolithic scaling as the primary path to more powerful chips — by decomposing complex systems into composable chiplets that can be independently designed, fabricated at optimal nodes, and combined through advanced packaging, the semiconductor industry is transcending the yield and cost limitations of monolithic die, making chiplet design competency the new essential skill for every chip architect and physical design team.