OpenCores

OpenCores is the world's largest open source hardware community developing digital open source hardware through electronic design automation, with a similar ethos to the free software movement. OpenCores hopes to eliminate redundant design work and slash development costs. A number of companies have been reported as adopting OpenCores IP in chips, or as adjuncts to EDA tools. OpenCores is also cited from time to time in the electronics press as an example of open source in the electronics hardware community, for example, while EE Times reported in late 2008 that OpenCores had passed the 20,000 subscriber mark. In October 2010 it reached 95,000 registered users and has approximately 800 projects.

History of OpenCores

Damjan Lampret, one of the founders of OpenCores states on his website that it began in 1999 [10]. The first public record of the new website and its objectives was on CNET News in 2001. Through the following years it was supported by advertising and sponsorship, including Flextronics.

In mid-2007 an appeal was put out for a new backer, and, in November of that year, Swedish design house ORSoC AB agreed to take over maintenance of the OpenCores website.

Licensing

In the absence of a widely accepted open source hardware license, the components produced by the OpenCores initiative use several different software licenses. The most common is the GNU LGPL, which states that any modifications to a component must be shared with the community, while you can still use it together with proprietary components. The less restrictive 3-clause BSD license is also used in some hardware projects, while the GNU GPL is often used for software components, such as models and firmware.

The OpenCores library

The library will consist of design elements from central processing units, memory controllers, peripherals, motherboards, and other components. Emerging semiconductor manufacturers could use the information and license designs for free.

Currently the emphasis is on digital modules called 'cores', commonly known as IP Cores. The components are used for creating both custom integrated circuits (ASICs) and FPGAs.

The cores are implemented in the hardware description languages Verilog, VHDL or SystemC which may be synthesized to either silicon or gate arrays.

The project aims at using a common non-proprietary system bus named Wishbone, and most components are nowadays adapted to this bus.

Among the components created by OpenCores contributors are:

• OpenRISC - a highly configurable RISC central processing unit
• Amber (processor core) - an ARM-compatible RISC central processing unit
• A Zilog Z80 clone
• USB 2.0 controller
• Tri Ethernet controller, 10/100/1000 Mbit
• Encryption units, for example DES, AES & RSA
• HyperTransport Tunnel
• A PIC16F84 core
• Zet: an x86 compatible core

Alternatives to the Opencores IP library include GRLIB and the Milkymist system on chip, both available under the GNU GPL.

OpenRISC ASIC

In April 2011 OpenCores opened donations for a new project to develop a complete System on a chip design based on the OpenRISC processor and implement it into an ASIC-component. OpenCores affiliated with OpenCores, for example OpenSPARC and LEON.

See also

• Open content
• Free content
• Open-source hardware
• Wishbone

External links

• Official Website