Silexica's FPGA Tools, Years After EIC Accelerator Funding

Silexica sold software that tells programmers how their code will behave on chips with many processor cores before they run it there. In the European Commission's 9 January 2019 round of the EIC SME Instrument Phase 2, the forerunner of the EIC Accelerator, the Cologne company won a grant for FuSy, a project to turn its SLX tools into what it called "the world's first Full-System Simulation tool" for autonomous driving, aviation and embedded vision, according to the Commission's list of selected companies, which names Silexica as the only beneficiary of the project. The EU contributed €1,989,197 to a €2,841,711.25 project that ran from 1 May 2019 to 30 April 2021, according to CORDIS.

Six weeks after the project ended, on 10 June 2021, the American chipmaker Xilinx announced that it had acquired Silexica, according to the acquisition announcement and the Dresden research centre cfaed, home of one of its co-founders. The price was not disclosed. Eight months later AMD completed its own takeover of Xilinx, according to AMD.

What Is Left of Silexica Today

Silexica no longer operates as an independent company, and its own website, silexica.com, no longer resolves. The legal entity still exists. The commercial register shows Silexica GmbH at Widdersdorfer Straße 260 in Cologne after an address change published in March 2022, and its balance sheets for 2021, 2022, 2023 and 2024 were published between May 2023 and August 2025, according to North Data, which also lists trademark filings for "Silexica" in May 2025 and "SLX" in May 2026. In July 2021, a month after the acquisition, the founders Maximilian Odendahl and Johannes Emigholz were removed as managing directors and Brendan M. Farley was entered in their place. The balance sheets are filed in the short form that small German subsidiaries may use, and their figures for equity, staff and results could not be read free of charge for this article.

At the time of the deal, Xilinx said it would fold Silexica's SLX FPGA tool suite into its Vitis software platform, the toolchain developers use to program its FPGAs (chips whose circuits can be reconfigured after manufacture) and adaptive systems-on-chip. Salil Raje, then head of Xilinx's data centre group, said the technology "complements our existing Vitis solution and roadmap", according to the announcement and Startbase. Neither Xilinx nor AMD has since said publicly which Vitis features come from Silexica, or whether SLX FPGA is still sold as a product; this could not be verified.

The Technology: Mapping Code Onto Many Cores

Modern chips for cars, drones and base stations combine several processor cores with specialised accelerators such as graphics processors, AI engines and FPGAs. Programmers usually write C or C++ for one core and then split the work across the others by hand, a slow process in which nobody can see in advance whether the hardware will be overloaded. The FuSy objective on CORDIS describes the alternatives as "laborious manual methods or unrealistic model-based tools".

Silexica's SLX tools analyse the source code itself, both statically and while it runs, to find the parts that can execute in parallel, and then estimate how the program will perform on a given chip. Co-founder Rainer Leupers told the European computing network HiPEAC that the work began as an academic research project around 2007, and Odendahl said Silexica was "the only ones not just using static code analysis, but adding dynamic source code analysis". In 2017 the company sold an SLX automotive package for spreading driver assistance code over multicore controllers and named Denso, Toyota, Fujitsu and Huawei as customers, according to Electronic Design; cfaed names Huawei and Samsung as early corporate customers.

By the time FuSy ran, the product had narrowed. SLX FPGA, released in versions such as 2019.4 in December 2019 and 2020.4 in January 2021, prepares C/C++ code for high-level synthesis, the process that turns software into FPGA circuits, inside Xilinx's own Vivado and Vitis flows. Silexica claimed an average 45-fold performance improvement for the 2019.4 release, and quoted an engineer at Fujitsu Kyushu Network Technologies as a user. In December 2020 it launched a plug-in for Xilinx's Vitis HLS compiler, with a Xilinx vice president quoted in the announcement. Before the sale, Silexica's main product was therefore built around a single chip vendor's tools.

What FuSy Promised, and What CORDIS Shows

The FuSy proposal set out a technical goal and a commercial one. Technically, SLX was to be "upgraded into a full-system simulation tool and its automotive application adapted", followed by a step-by-step launch in automotive, embedded vision, and aviation and defence. Commercially, Silexica expected "a turnover of €36.3M (of it €34.9M with FuSy) and a staff count of 210 employees by 2024", according to the CORDIS fact sheet.

The only published periodic report, for May 2020 to April 2021, says Silexica "developed a full system simulation environment" and extended its analysis with a performance simulation framework for GPUs, AI accelerators and FPGAs, and that "product readiness was successfully proven" through testing. The automotive adaptation named in the objective does not appear among the results, and the report's market plan had become a roll-out in "automotive, embedded vision/ robotics, aerospace etc." A CORDIS results article, last updated in February 2022, quotes project coordinator Raphael Bruns, by then at Xilinx, as saying the tool beat a hand-optimised post-quantum cryptography design from the US National Institute of Standards and Technology by 43% and cut three months of manual work to a couple of days. That figure comes from the company and has not been independently published.

1. Full-system simulation in SLXDeliveredSimulation framework for GPUs, AI accelerators and FPGAs reported in the final period report.
2. Automotive application adaptedNot shownNot mentioned among the reported results; the products launched in 2019 to 2021 targeted FPGA design.
3. Launch in automotive, vision, aviation and defencePartlySLX FPGA releases and a Vitis HLS plug-in shipped; no sector launch announced.
4. €36.3M turnover and 210 staff by 2024Not achievedNever reported; the company was absorbed by Xilinx in 2021 and files short-form balance sheets only.
5. Project on scheduleOn timeRan its full term, 1 May 2019 to 30 April 2021, per CORDIS.

Read fairly, FuSy delivered what a grant can buy: the simulation technology was built and shipped in a commercial product line, on schedule. The plan to build a large European tools company did not happen. The report filed at the end of April 2021 still spoke of reaching "more than 200 EU-based employees by 2024"; within six weeks the company had been sold.

The Money Behind Silexica

Silexica was well financed before the EU grant. Seed Fonds Aachen and DSA Invest backed it in 2015; Merus Capital and Paua Ventures co-led an $8 million Series A in 2016; and EQT Ventures led an $18 million Series B in June 2018, with all earlier investors joining, according to Global Venturing and the law firm Osborne Clarke, which advised EQT. Both put the total raised at $28 million, the figure Xilinx repeated in 2021. The disclosed rounds add up to $26 million; the size of the seed round was not published.

Public money came earlier too. North Data, drawing on the German federal funding catalogue, lists an EXIST research transfer grant of €179,932 from June 2016 and Silexica's shares in three federally funded research projects: ARAMiS II on safety-critical multicore systems (€341,168), PARIS on parallel software for automated driving (€208,758) and EM-RAM on energy-efficient mapping for multiprocessors (€202,203). CORDIS lists no EU project for the company other than FuSy. The SME Instrument award was grant only, and no investment by the EIC Fund in Silexica has been announced; the Fund was set up in 2020.

Why Europe Should Care

Programming tools for complex chips are part of the semiconductor supply chain that the EU now treats as strategic; its Chips Act entered into force on 21 September 2023. Silexica is a clear case of how such know-how leaves European ownership. Six years of university research, German federal grants and a €1.99 million EU grant produced a Cologne tools company, and its technology went to a US chipmaker shortly after the EU project closed. The Cologne entity survives, and CORDIS reported in early 2022 that the team was "expanding rapidly" under Xilinx, so the work and at least part of the jobs stayed in Germany. The intellectual property and the product roadmap are now AMD's.

The Verdict

Silexica, Xilinx and AMD have not been asked for comment for this article. It is based entirely on public records, company statements and EU project data, linked throughout.