The popularity of field-programmable gate arrays (FPGA) has grown in recent years due to their potential performance advantages over sequential software, and as a prototyping platform for application-specific integrated circuits (ASIC). Vendors such as Xilinx offer automated tool suites that can be used to program FPGAs based on a RTL description. These tool suites are sufficient forgeneral users, but they usually don't provide the opportunity to integrate custom computer-aideddesign (CAD) tools into the regular design flow. Xilinx first offered this capability in their ISE tool suite with the Xilinx Design Language (XDL). Using XDL, a Xilinx design could be extracted from the regular CAD flow, run through an external tool, and injected back into the flow. Research tools targeting commercial FPGAs have most commonly been based on XDL. Vivado (Xilinx's newest tool suite) no longer supports XDL, preventing similar tools from being created for next-generation devices. Instead, Vivado includes a Tcl interface that exposes Xilinx's internal design and device data structures. Considerable challenges still remain to users attempting to leverage this Tcl interface to develop external CAD tools. This thesis presents the Vivado Design Interface (VDI), a set of file formats and Tcl functions that address the challenges of exporting and importing designs to and from Vivado. To demonstrate its use, VDI has been integrated with RapidSmith2, an external FPGA CAD framework. To the best of our knowledge this work is the first successful attempt to provide an opensource tool-flow that can export designs from Vivado, manipulate them with external CAD tools, and re-import an equivalent representation back into Vivado.



College and Department

Ira A. Fulton College of Engineering and Technology; Electrical and Computer Engineering



Date Submitted


Document Type





Vivado, FPGA, Tcl, CAD, RapidSmith2, Xilinx, Java