offering certain functional blocks. Typically, the customers are semiconductor companies or module developers with in-house semiconductor development. A company wishing to fabricate a complex device may license in the rights to use another company's well-tested functional blocks such as a microprocessor, instead of developing their own design, which would require additional time and cost. The Silicon IP industry has had stable growth for many years. The most successful Silicon IP companies, often referred to as the Star IP, include ARM Holdings and Synopsys. Gartner Group estimated the total value of sales related to silicon intellectual property at US $1.5 billion in 2005 with annual growth expected around 30%. IP hardening IP hardening is a process to re-use proven designs and generate fast time-to-market, low-risk-in-fabrication solutions to provide Intellectual property (IP) (or Silicon intellectual property) of design cores. For example, a digital signal processor (DSP) is developed from soft cores of RTL format, and it can be targeted to various technologies or different foundries to yield different implementations. The process of IP hardening is from soft core to generate re-usable hard (hardware) cores. A main advantage of such hard IP is its predictable characteristics as the IP has been pre-implemented, while it offers flexibility of soft cores. It might come with a set of models for simulations for verification. The effort to harden soft IP requires employing the quality of the target technology, goals of design and the methodology. The hard IP has been proven in the target technology and application. E.g. the hard core in GDS II format is said to clean in DRC (Design rule checking), and LVS (see Layout Versus Schematic). I.e. that can pass all the rules required for manufacturing by the specific foundry. Free and open-source Since around 2000, OpenCores.org has offered various soft cores, mostly written in VHDL and Verilog. All of these cores are provided under free and open-source software-license such as GNU General Public License or BSD-like licenses. Since 2010, initiatives such as RISC-V have caused a massive expansion in the number of IP cores available (almost 50 by 2019). This has helped to increase collaboration in developing secure and efficient designs. See also List of semiconductor IP core vendors Semiconductor Semiconductor fabrication plant (foundry) Mask work Fabless manufacturing Integrated circuit layout design protection References External links Open cores "design and publish core" (under LGPL Licence) Altera cores Free reference IP cores for