Advanced Boolean Expression Language

A preprocessor with syntax loosely based on Digital Equipment Corporation's MACRO-11 assembly language is also included.

In addition to being used for describing digital logic, ABEL may also be used to describe test vectors (patterns of inputs and expected outputs) that may be downloaded to a hardware PLD programmer along with the compiled and fuse-mapped PLD programming data.

The ABEL concept and original compiler were created by Russell de Pina of Data I/O's Applied Research Group in 1981.

The work was continued by ABEL product development team (led by Dr. Kyu Y. Lee) and included Mary Bailey, Bjorn Benson, Walter Bright, Michael Holley, Charles Olivier, and David Pellerin.

[2] Xilinx discontinued support for ABEL in its ISE Design Suite starting with version 11 (released in 2010).

An ABEL HDL description of a 4-bit counter.