The Very High Speed Integrated Circuit (VHSIC) Hardware Description
Language (VHDL) is the product of a US Government request for a new
means of describing digital hardware. The Very High Speed Integrated
Circuit (VHSIC) Program was an initiative of the Defense Department to
push the state of the art in VLSI technology, and VHDL was proposed as
a versatile hardware description language.
The contract for the first VHDL implementation was awarded to the team
of Intermetrics, IBM, and Texas Instruments in July 1983. However,
development of the language was not a closed process and was subjected
to public review throughout the process (accounting for Versions 1
through 7.1). The final version of the language, developed under
government contract, was released as VHDL Version 7.2.
In March 1986, IEEE proposed a new standard VHDL to extend and modify
the language to fix identified problems. In December 1987, VHDL
became IEEE Standard 1076-1987. VHDL was again modified in September
1993 to further refine the language. These refinements both clarified
and enhanced the language. The major changes included much improved
file handling and a more consistent syntax and resulted in VHDL
Standard 1076-1993.
