In the Jurassic period, all oscilloscopes and logic analyzers were big, bulky, bench instruments that were incredibly expensive. But a decade or so ago a variety of low-cost scopes and analyzers appeared. They are not analogous to the little shrew-like mammal that replaced the dinosaurs, since the high-end devices are essential for lots of engineering work and will never disappear. Instead, these USB-connected instruments fill a niche for those with limited budgets who are not working on bleeding-edge projects. Over the years I've reviewed a number of these.
The Logic 16 will fit nicely in a purse for ad hoc debugging sessions at wedding receptions and cocktail parties.
Saleae's new Logic 16 is a 16-channel USB-based logic analyzer (LA). It's one of the very few cross-platform LAs available, with application software that runs under Windows, Linux, and on the Mac.
Its speed is a function of the number of channels being used. With three, the unit clocks data in at up to 100 MHz. Nine channels (somewhat puzzling; one would think eight would be more likely) drops it to 32 MHz, and half that speed is attainable when all 16 channels are in use.
With all of the crazy voltage levels now used in digital circuits, it's nice that Logic supports two voltage ranges: 1.8 to 3.6 V and 3.6 to 5 V.
Capture data is streamed through short on-device buffers to the host computer, which can handle up to 1 TB of data given minimal transitions (the data is compressed). As a practical matter, the software suggests that most host computers can handle up to about 1.8 GB. Like with all of these USB devices one must not overrun the USB connection, but I had no problems at all using a four-year old MacBook Pro with a 16 MHz acquisition rate.
Click on image to enlarge.
Screen shot of the Logic 16's interface.
A built-in protocol analyzer decodes CAN, DMX-512, I2C, I2S/PCM, Manchester, 1-Wire, async serial, simple clocked parallel, SPI, and UNI/O.
The Logic 16 comes in a stunning metal case with non-slip rubberized bottom. It's spare, like an iPhone. Beautiful. There are no controls, just connectors for the probes and USB, and one LED. It comes with a zip-up carrying case that is so elegant it could be a haut-couture fashion accessory. And it will all fit nicely in a purse for those ad hoc debugging sessions that always seem to come up at wedding receptions and cocktail parties.
Unlike some USB LAs, the Logic 16 does come with micro-grabbers for each of the channels and ground.
Originally published on Embedded.com. Read the full blog here.