VHDL (VHSIC (Very High Speed Integrated Circuit) Hardware Description Language) is a hardware description language used in electronic design automation to describe and design digital systems such as field-programmable gate arrays and integrated circuits.
VHDL is turned into logic through a process called synthesis.
- Wikipedia's article on VHDL
- The Hamburg VHDL Archive
- wikibook programmable logic/VHDL
- Free model foundry - a collection of VHDL/Verilog models of existing chips.
- Stack Overflow documentation for VHDL