If you want to know if an embedded system design book really talks about everything you need to know, I recommend you look for the word "watchdog" in the index. If it's not there, move on to the next book.
Let me explain...
There is a lot of confusion in the education and book market about the difference between learning about the underlying technology of embedded systems and learning how to build embedded systems. I think the difference is critical, because you are going to have trouble succeeding with complex embedded system projects if you are missing skills in the area of system integration and system architecture.
A book about the technology of embedded systems talks about how microcontrollers work, how analog to digital conversion works, interrupts, assembly language, and those sorts of things. In other words, it gives you the building blocks of the basic technology. This is essential information. But, it isn't enough to succeed when you get beyond relatively small and simple projects. If you took a course in college that was a typical entry-level "Introduction to Microcontrollers" course, this is what you might have seen. Again, it was essential, but far from complete.
A book about how to build embedded systems also talks about the parts that make the system function as a whole. For example, it explains how to address difficult areas such as concurrency management, reliability, software design, and real time scheduling. It need not go into serious depth about underlying theory if it is an introductory book, but it should at least give some commonly used design patterns, such as using a watchdog timer. In other words, it helps you understand the system level picture for building solid applications rather than just giving the basic technology building blocks.
There are other areas that I think are critical to designing good embedded systems that aren't covered in most embedded design books. Most notable is a notion of lightweight but robust software processes. There aren't many books that really cover everything. But, knowing what you don't know (and what a textbook leaves out) is an important step to achieving higher levels of understanding in any area.
If you learned embedded systems from a book or college course that didn't even mention watchdog timers, then you missed out a lot in that experience. You might or might not have found and filled all the gaps by now. Do yourself a favor and take a look at a book that covers these topics to make sure you don't have any big skill gaps left. If you think the "watchdog test" isn't fair, give your favorite book a second chance by looking for keywords such as statechart, mutex, and real time scheduling. These are also typical topics covered in books that talk about system level aspects rather than just building blocks.
Companion blog to the book Better Embedded System Software by Phil Koopman at Carnegie Mellon University
Monday, August 2, 2010
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Nice post, I teach a course that's more along the lines of "how to design" and agree with this.
ReplyDeleteWhat are the good books in this space besides yours? I like Gannsle's _Art of Designing Embedded Systems_ quite a bit.
In fact, my answer would have been Jack Gannsle's book even if you hadn't mentioned it. A few of the texts in this area do manage to cover most of the technical topics, but most of them are too light on high level technical perspective. That's one of the reasons I decided to spend a few months of my life writing my book.
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