Floorplanning With Stacked Silicon Interconnect (SSI) Devices - 2021.1 English

Vivado Design Suite User Guide: Design Analysis and Closure Techniques (UG906)

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2021.1 English

There are extra considerations for Stacked Silicon Interconnect (SSI) parts. The SSI parts are made of multiple Super Logic Regions (SLRs), joined by an interposer. The interposer connections are called Super Long Lines (SLLs). There is some delay penalty when crossing from one SLR to another.

Keep the SLRs in mind when structuring the design, generating a pinout, and floorplanning. Minimize SLL crossings by keeping logic cells of critical timing paths inside a single SLR.

Figure 1. Minimize SLR Crossings

The I/Os must be placed in the same SLR as the relevant I/O interface circuitry. You must also carefully consider clock placement when laying out logic for SSI parts.

Recommended: Let the placer try an automatic placement of the logic into the SSI parts before doing extensive partitioning. Analyzing the automatic placement may suggest floorplanning approaches you were not considering.