Opinion

Jeff Bier’s Impulse Response—Fried Fahrvergnügen

Do you ever look at a piece of hardware and wonder, “Why, oh why, did they build it like that?”  This is what I’m thinking as I look at my 2001 Volkswagen Passat, a car that is now completely dysfunctional because of an unfortunate (yet easily foreseen) intersection of water and electronic circuitry.  Let me explain. The car has a sunroof, and the sunroof has two gutters and tubes that route rainwater through the body of the car and dump it outside. But like all gutters, they can get plugged Read more...

Jeff Bier’s Impulse Response: When Worlds Collide

When I was a kid, 10,000 lines of code was considered a decent-sized application. Now, it seems, we’re on the verge of seeing applications with 10,000 threads. Or at least, that’s what graphics chip maker Nvidia is envisioning. Nvidia recently announced the Tesla product family, which includes a chip with 128 processors and hardware support for execution of thousands of threads. Like other Nvidia chips, Tesla is a graphics processing unit (GPU), but this new chip is not really targeting Read more...

Jeff Bier’s Impulse Response—Revisiting Heterogeneous vs Homogeneous

Back in 2001 I wrote a column about the merits of using heterogeneous designs for signal processing-oriented applications.  My argument went like this: signal processing applications typically encompass diverse data rates, data types, and algorithms, and it often makes sense to address these needs using a collection of similarly diverse processing engines rather than taking a one-size-must-fit-all approach. Back then, using a heterogeneous processing architecture usually meant using two or Read more...

Jeff Bier's Impulse Response—All Video Apps are Not Alike

Pretty much everyone agrees that digital video has become a killer app for embedded processing engines. But “video” can mean different things to different people; the term encompasses a diverse set of applications with very different requirements. A processor you’d use for video playback in a low-cost cell phone, for example, isn’t going to cut it for an HDTV set and vice versa. System developers and their chip suppliers must understand exactly what kinds of video they need to handle, and Read more...

Jeff Bier’s Impulse Response—Signal Processing Algorithms Easier to Create, Harder to Sell

  One of the things I really love about digital signal processing technology is how, year by year, it gets easier to create new things.  Things like clever new audio or video compression algorithms, for example. Forget about needing mainframes, minicomputers, or expensive engineering workstations to evaluate that new algorithm. Today we’ve got powerful PCs and easy-to-use simulation environments that make the whole process relatively painless. Forget about the time, money, and risk Read more...

Jeff Bier’s Impulse Response—DSP Vendors Need Multi-Core Tools Strategy

There’s been a lot of press lately about start-up companies offering multi-core DSP chips.  What’s less widely discussed is that large, established DSP chip vendors have been offering multi-core DSP chips for years.  These chips have been popular in “channelized” applications where workload partitioning is fairly straightforward. But as multi-core DSPs move into a wider range of applications—and as the number of cores per chip grows—partitioning workloads among cores is becoming much Read more...

Jeff Bier’s Impulse Response—As Signal Processing Workloads Evolve, So Must Processors

Historically, DSP processors have been the default choice for signal processing applications because they could efficiently process classical signal processing functions like FIR filters and FFTs. But those capabilities aren’t enough any more. Signal processing applications still include demanding real-time filtering and frequency transforms, but these algorithms are increasingly combined with processing that is fundamentally different. For example, algebraic signal processing computations Read more...

Jeff Bier’s Impulse Response—Efficiency Comes in Many Flavors

It’s generally accepted that, for processing engines, there is a trade-off between efficiency and generality.  The more a chip is geared towards a specific application, the more efficient it’s likely to be (in terms of speed, energy consumption, and cost).  On one end of the spectrum you have traditional FPGAs, which are completely general-purpose, and on the other are fixed-function chips, which are completely application specific. In between these extremes lie various types of processors, Read more...

Jeff Bier’s Impulse Response—Efficiency Comes in Many Flavors

These days, there are so many start-ups developing programmable processors that it feels like we’re back in the “bubble” years, when anyone with a remotely viable processor design could secure venture funding. A pivotal question for the current crop of start-ups is whether to offer their processors as flexible, general-purpose chips, or as highly specialized, application-specific solutions. Should it be a jack-of-all-trades, or a master of one? If the processor is complex or the programming Read more...

Jeff Bier’s Impulse Response—Signal Processing Isn't a Commodity

At the Consumer Electronics Show last month I was struck (not for the first time) by the number of consumer electronics products that rely on digital signal processing—at this point, nearly all of them. In fact, so many of today's products incorporate digital signal processing-based functions that it's tempting to start viewing these functions as commodities. But in most cases, DSP functions aren't going to become commodities anytime soon. They may be ubiquitous, but they're not Read more...