AHD LANGUAGES - A MUST FOR TIME-CRITICAL DESIGNS

In this article, Brian Antao of Motorola Inc., presents an overview of the state-of-the-art in analog modeling and hardware description lang uages. The emphasis is on higher-level circuit and system behavioral m odels for modeling complete analog and mixed analog-digital systems. A n essential component required for this level of modeling is a Hardwar e Description Language (HDL) to encode the models in a consistent mann er which can be later simulated as well as used for design documentati on. Hardware Description Languages are a prominent feature of the digi tal design process, and the newer generation of the mixed analog-digit al systems require compatible hardware description language support th at provides for the analog sections. Two popular digital HDLs are VHDL and Verilog. To provide natural extensions to these existing digital standards, analog hardware description language (AHDL) standardization efforts ae underway to develop analog extensions to VHDL, called VHDL -A, and to Verilog, called Verilog-A.