Embedded Systems Design - July 2008 - (Page 9)

parity bit Better than pulp ﬁction Q uite an issue! (June 2008 issue of Embedded Systems Design, www.embedded. com/2008/0806.) First all the hooplah generated by Dan O’Dowd’s article (sort of like an infomercial in print) on embedded Linux was very entertaining! Even a hardware guy like me could see through O’Dowd’s self-serving bending of the truth, shall we say. Glad to see lots of If a software system were others weren’t fooled either. And it was good to see 95% off-the-shelf components and Jim Turley in print again. 5% glue logic, it would be easy to His article questioning the recreate, demonstrating that the hardware-independence of company had nothing to offer. the Internet shined some light on some things most ware? Do you have any good ideas, of us probably don’t often think Jack? about. —Jim Ford Last, but certainly not least, Jack Broadcom Corp. Ganssle’s article “Faster!” hit the nail Irvine, CA on the head as usual. I read Tracy Kidder’s excellent Soul of a New Machine Embrace the complexity in 2001, about 20 years after it was In his June column, Jack Ganssle written. I could relate to it greatly, es(“Faster!”, June 2008, p. 53, www.empecially due to the fact that I had worked at a now-defunct startup. For- bedded.com/208400913) asks whether the software IC is even possible. It’s tunately, since then I’ve been working easy to demonstrate that it’s not. All at larger companies where 65+ hour software components (particularly the workweeks are rare. They still happen off-the-shelf kind) involve tradeoffs. If occasionally, but they’re rare. People, you use small components, you’ll need including my wife, still don’t undera lot of them, and hence a lot of glue stand the rationale behind the comlogic—thus defeating the purpose. If pulsion. components are large, they’re either Interesting that Jack came to the rigid and unlikely to ﬁt your needs or conclusion that software design needs highly conﬁgurable and therefore very some breakthroughs in tools and complex to understand, integrate, and reuse. From the hardware-design side, maintain. Then there are the issues of we could also use a boost in the tools area, at least as far as design software is source-code availability, royalties, and the fact that you’re more dependent concerned. Reuse is a different story. on outside vendors. It’s rather amusing to a hardware jock But the software/IC analogy is aclike me that it’s even an issue in software! Design reuse in hardware is a to- tually ﬂawed at a deeper level: if software were like integrated circuits, the tal no-brainer! Why is there so much difference between hardware and soft- best-designed systems I’ve worked on would have their equivalent in several hundred ASICS, each approximately the complexity of the Z80, but all different and highly interconnected. Furthermore, during development (and after release), both the ICs, the interconnections among them, and even the number of pins would be changing on a weekly basis as the market’s needs evolve. Hardware ICs simply aren’t a good model for software. Additionally, if a company wants to differentiate itself from the competition, it has to produce most of its software internally so that the effort it expends and the expertise it possesses will show up in the end product. If a software system were 95% off-the-shelf components and 5% glue logic, it would be easy to recreate and would demonstrate that the company had nothing to offer itself. Internally written components are a good idea but expensive to get right. Unless you’re using the same hardware, user interface, etc., over and over, you’ll ﬁnd yourself writing large numbers of new components for each new system, hence nothing is gained. Software development is the encoding of messy, domain-speciﬁc, real-world knowledge into machineusable form and is unique among human endeavors. Its incredible ﬂexibility is also unique—and is its greatest strength. Our desire to formulate simple solutions just proves that we don’t really understand it yet. The sooner we accept that it’s different, the sooner we can move forwards. —Grant D. Schultz Senior Software Engineer ScriptPro Mission, KS We welcome your feedback. Send your comments to Richard Nass at rnass@ techinsights.com or go to our online forum. www.embedded.com | embedded systems design | JULY 2008 9 http://www.embedded.com/2008/0806 http://www.embedded.com/2008/0806 http://www.embedded.com/208400913 http://www.embedded.com/208400913 http://www.embedded.com

Table of Contents Feed for the Digital Edition of Embedded Systems Design - July 2008

Embedded Systems Design - July 2008 Contents #Include Parity Bit Programming Pointers Interactive C-code Cleaning Tool Supports Multiprocessor SoC Design Building a Power Supply for Discontinuous Transmission Wireless Networks An Exception Primer Advertising Index Break Points Marketplace

Embedded Systems Design - July 2008

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