Customer Reviews

The Designer's Guide to VHDL, Second Edition (Systems on Silicon)

5 star:		(14)
4 star:		(7)
3 star:		(1)
2 star:		(0)
1 star:		(3)

 

 

Until Peter's next book comes out of course! I would give it 5 stars if I was just learning the VHDL language, but I'm actually trying to use VHDL for FPGA design and this book falls short in that regard.

This book is really good at explaining the 'mechanics' of VHDL programming. It is an out growth of Peter's "Intro to VHDL" paper that was published on the web and it sort of shows. I really like the depth that it goes into, I wish it had the standard libraries in the appendix. (it doesn't) However, until getting Ashendon's book, all other VHDL texts were pretty opaque.

The only thing this book does not have is a treatment of logic 'inference.' Since all VHDL compilers today "infer" (a fancy way of saying "guess") what logic would be able to implement a behavior, not understanding how those compilers guess makes it possible to write syntactically clean VHDL that doesn't synthesize any logic. To get a better handle on inference I'd recommend "HDL Chip Design" by Smith.

Before Ashenden there was Douglas Perry. Perry's book on VHDL (Second Edition) was pretty well written and handled HDL for synthesis quite well. After Perry, I was introduced to Ashenden's "The Designer's Guide to VHDL". This is by far the must have VHDL reference manual. Ask yourself, what is important in a good reference manual...the answer is well organized concepts, good examples and a thorough index! This book has it all. I have other VHDL books that just get dusty on my shelf, not this one! If I'm not using it, someone else usually wants to borrow it. If your looking for a great VHDL book...pick this one up or borrow it.

This book has a very detailed and complete coverage of the VHDL langauge. The book is clearly geared to the beginner and serves as a great tutorial on the language, however the depth is good enough that even a seasoned VHDL programmer will find it of good benefit both at increasing their depth in the language and also as a desk reference. My main criticism of the book is that I found it somewhat verbose in description on certain topics. While the detail is needed on the more complex or subtle topics, it seems to drag on with some of the more trivial ideas. In any case, the good clearly wins out in an overall must have VHDL reference.

I have a couple of other VHDL books but I can't find them, for some reason I have two of copies of 'The Designer's Guide to VHDL'. When reading this book it is apparent that Ashenden thoroughly understands VHDL - excellent examples and I really like the VHDL-93 viewpoint with the VHDL-87 differences sprinkled throughout. If you really want to learn to design first-class test benches, you need this book. It has text IO coverage and in depth information on components, configurations and packages.

Too many VHDL books dilute their point by trying to double as logic design texts. The problem is that VHDL is a complex (or "rich") language, and needs an intense focus of its own. This book does the best job I've seen.

I've learned lots of languages, usually one or two a year. I know what to look for. I want a book that lays it all out clearly enough that I can find what I want. That includes complex data types, overloading, and especially configurability. VHDL really does have almost all the capabilities of a C-like language, plus a few more features, and the author has succeeded in making them accessible.

Configurability deserves special attention - it is an explicit part of the VHDL language. It's a pre-Object-Oriented language but was developed when OO ideas were solidfying in the industry. Although it lacks OO flexibility, Ashenden does point out how "use" and "configure" can give a few of the same effects.

Hardware description languages aren't like regular programming languages, and shouldn't be, and can't be. Still, they're not that different, either. Perhaps you're already a good programmer and already comfortable with digital system basics. If so, this may be the book to give you the language knowledge you need with minimal repetition of what you already know.

This book goes into great detail on variable typing, subtyping, and all aspects of behavioral modeling. It's extremely detailed and thourough. If you just want to learn the intricacies of VHDL and only expect to write test benches and behavioral models, this is definitely the book for you. If you're looking for a practical book that will help you to write synthesizable code, look somewhere else. The book does have a 17-page appendix on synthesis, but that's pretty much it. All the "case studies" are behavioral, even the RTL models.

VHDL is used for a wide variety of things - almost none of them what VHDL was every really meant for. This makes finding a useful text a reference a significant chore. Ashenden sometimes seems to move at a snail's pace - the text is written more as a tutorial than a reference. In some ways this is good, really the syntax of VHDL and the constructs are quite simple. His repeated examples make it clear there really isn't much magic going on. Personally I wish the book was more directed at synthesis - because that's what I use it for - but this text is more directed at the language. So some supplementing of the text will be necessary.

In short, it could be better but I'm not sure how and for my requirements it appears to be about the best the market has to offer.

I have borrowed this book many times from the library but never was able to read it thouroughly. This is a very complete book and you can have it for a complete reference. However, this book is too much for somebody (like me) needing VHDL for IC design instead of a complete VHDL language reference (remember logic synthesis only use a subset of what VHDL is offering). Also this book seems to be too much for a beginner.

In short, this is an excellent for VHDL languange reference, but if you are a beginner and/or need VHDL for logic synthesis without a complete VHDL language reference, you may not need this book.

Ashenden covers many of the finer points of the VHDL language including differences between '87 and '93 implementations. I have used suggestions from his book with Cadence, Synopsys, Altera, Xilinx, and Model Tech tools for several years without any problems(all source code for the book is available at his web site). In addition, this is one of the few books to handle text and file I/O adequately, a real necessity for test bench design. Along with Kevin Skahill's and Douglas Smith's(dual Verilog/VHDL coverage, real handy) books it's definitely in the top 3.

The Designer's Guide to Vhdl, by Peter J. Ashenden is a very good book for all level of Vhdl programming. Tutors the basic to advance level programming in Vhdl. Extensively covers the Behavior Modeling by many examples and case studies. If you are looking something on synthesis, this book does not cover whole lot on it, but it's worth buying for reference since the price of the book is not that expensive compare to others.