So what do you do? Personally, I usually start by taking a wild guess based on what I'm seeing and leap into the debugging fray with gusto and abandon. If this fails, I pull back and start a more rigorous analysis, but it's surprising how often one's initial guess bears fruit. For example, maybe you have a nagging doubt that the external reset to a particular device is not being asserted quite as long as the specification assured you it was going to be. Whichever debugging approach you adopt, at some stage you'll probably want to wheel out a logic analyzer and take a closer look.

The meanest beast available
The next move in the game is to choose your logic analyzer. For some problems there is no alternative but to use the biggest, meanest beast available -- the ultra-fast monster with more channels and capture depth than you can swing a stick at. So you set off on a lonely stroll down the corridors trying to find out who had it last and where they've hidden it. (In some cases - say if you haven't played with it for a while - you may also need to locate the one guy or gal who actually knows how to work the brute, which sometimes appears to have more controls than a light aircraft.)

On the other hand, not all problems require us to wheel out the heavy artillery. In these cases, we can put together a simple wish list, which may well include "ease of use," "fast sampling speed," and last-but-not least "personal." In the latter case, we all know that sharing a piece of test equipment is like sharing a stapler -- it's OK in theory, but you can never find the little rapscallion, or someone else is already using it when you need it.

The answer to this conundrum may well be the Ant8 from a company called RockyLogic. Released only a few weeks ago in December 2002, this tiny USB-based (and powered) device is around the size of a small box of matches, but it can sample eight channels at 500 million samples-per-second (Figure 1).

Figure 1 -- The matchbox-sized Ant8

At only $166 -- which is better than 3 million samples-per-second-per-dollar -- this little beauty is cheap enough to allow most engineers to own their own.

I want one of these
What has changed to make this level of technology available? One factor is the availability of highly integrated USB interface silicon. In the case of the Ant8, RockyLogic chose to use an interface chip from silicon boutique FTDI; they opted for this solution to leverage the software support and free drivers supplied by FTDI.

Another factor is the feature set provided in modern FPGAs such as the Virtex family from Xilinx. These devices are pretty much ideal for the Logic Analyzer application, because they have substantial on-chip memory, an on-chip DLL for clock generation, and abundant logic for a deeply pipelined implementation.

The Ant8 works with Windows 98, ME, 2000, or XP, and it requires either a USB socket on the main PC or a socket on a powered USB hub. It also comes equipped with an integrated display application (Figure 2) and this software will be upgradable via the Internet as new releases become available.

Figure 2 - Integrated display application

The initial application is monolithic. However, based on user feedback, RockyLogic is working on separating the GUI and back-end software such that the Ant8 can be driven by any program (this is currently in testing). The software is also being enhanced to allow remote control of the Ant8 across a network, and Linux support may be added in the not-so-distant future depending on customer demand.

Well, I don't know about you, but personally I think that this is a Cool Beans type of product, and I hope to add one to my personal collection before I'm very much older (unfortunately I first need to pay for the PIC microcontroller simulator and development board that I recently invested in). Until next time, have a good one!

Clive (Max) Maxfield is president of Techbites Interactive, a marketing consultancy firm specializing in high-tech. Author of Bebop to the Boolean Boogie (An Unconventional Guide to Electronics) and co-author of EDA: Where Electronics Begins, Max was once referred to as a "semiconductor design expert" by someone famous who wasn't prompted, coerced, or remunerated in any way.