Field-programmable gate array

A Field-Programmable Gate Array (FPGA) is a general purpose logic matrix configurable integrated circuit. It consists of a collection of logic gates that can be connected together in an almost unlimited number of combinations to produce custom operations that would normally only be possible with full-custom integrated circuits. Since FPGAs are produced in high volume, they can bring economies of scale to one-off and low volume projects.

Several open hardware projects use FPGAs, such as

• Minimig FPGA
• ...
• Balloon Xscale + FPGA board
• The Open Graphics Project (OGP) is developing graphics cards with fully published specs and open source drivers. Since the first version will be a FPGA, is also collecting information on FPGA programming and interfacing.
• ...
• ... (Add other open hardware projects I'm forgetting to this list)

Verilog ... Xilinx ... Altera ... Lattice ...

Verilog

Verilog is a hardware description language (HDL) used to model electronic systems. The language (sometimes called Verilog HDL) supports the design, verification, and implementation of analog, digital, and mixed-signal circuits at various levels of abstraction.

VHDL

VHDL (VHSIC hardware description language) is commonly used as a design-entry language for designing digital circuits as field-programmable gate arrays (FPGAs) and application-specific integrated circuits (ASICs).

Further reading

• Wikipedia: field-programmable gate array
• The Open Graphics Project wiki: The Open Graphics Project (OGP) is developing graphics cards with Free-licensed specifications and Free Software drivers. The FPGA development board OGD1, Revision B, uses a Xilinx® Spartan™-III XC3S4000 FPGA (primary FPGA) and a Lattice® LFXP10 non-volatile FPGA (PCI interface)
• "Project VGA": Home of the Low Budget, Open Source, VGA Compatible video card. Uses Xilinx Spartan 3 s400 FPGA.