Introduction to VHDL-AMS. 1. Structural and discrete time concepts

This paper provides an introduction to VHDL and its application to control system problems. Particular emphasis is placed on the use of VHDL-93 and the impact of discrete time and unidirectional flow. By adapting control systems problems to the discrete time constraints of VHDL, considerable simulation speed advantage is realized over the more complete solution of simultaneous equations possible with VHDL-AMS. The basic structure of VHDL is explored, and several examples are included to illustrate critical points. Finally, the modifications needed to VHDL to accommodate the more general needs of analog electronic and other systems are briefly introduced (VHDL-AMS).