The Designer's Guide to VHDL, 2nd Edition

Peter J. Ashenden


by Paul Menchini, Durham, North Carolina

In the five years since the publication of the first edition of The Designer's Guide to VHDL, the pressures on designers leading to the initial creation of VHDL have continued to increase. Electronic systems have become pervasive in consumer and business appliances, with ever-tighter constraints on cost, performance and schedule. Medical and aircraft systems, where correctness and reliability concerns are paramount, are now heavily reliant on digital electronic controls. New and larger field-programmable devices have opened up entirely new application domains, with the concomitant need for new groups of designers to learn VHDL. At the same time, the commercial lifetime of any given design continues to shrink, as new and improved versions of or competitors to a product enter the marketplace with increasing rapidity.

In response, there have been many changes to VHDL. Although the base language has remained relatively stable, with the only changes being a reworking of the shared variables of VHDL-93 and a number of bug fixes and other, minor updates coming in VHDL-2001, there has been much activity in related areas.

A number of new packages and standards built on top of the basic language have been developed: numeric_bit, numeric_std, math_real, math_complex and vital. VHDL-AMS, a superset of VHDL, extends VHDL to the domain of analog and mixed-signal modeling. A first-level standard synthesis subset has been defined, and work is underway to extend this definition to add more capability. These additions make VHDL uniquely capable of the modeling required of systems on silicon.

In this second edition of The Designer's Guide to VHDL, Dr. Ashenden builds upon the considerable strengths of the first edition by addressing all of these changes (with the exception of VHDL-AMS, which will be the subject of another volume in the Morgan Kaufmann Series in Systems on Silicon). He describes, in detail, the new packages adopted by the IEEE since the first edition, the new implementation of shared variables adopted in 2000 and the changes coming with VHDL-2001, now in the final stages of approval. The appendix on synthesis has been completely rewritten to correspond to IEEE Standard 1076.6, the standard synthesis subset description.

In addition, the DLX processor case study has been revised to more closely follow current design practices, and to allow a synthesizable version of the processor model to be more easily derived.

Finally, this new edition is made even more valuable by the inclusion of all source code on a CD-ROM, which also accesses FTL System's Exploration simulator.

The second edition of The Designer s Guide to VHDL sets a new standard in VHDL texts. I am certain that you will find it a very valuable addition to your library.