Apr 29, 2014

Meshing With Bluetooth

posted by Bryon Moyer

A while back, we took a look at what seemed to be the dominant two radio protocols in new Internet-of-Things announcements: Bluetooth Low Energy and WiFi.

Which resulted in Zigbee raising their hands and doing a virtual “Ahem…”

So I followed up with a discussion of Zigbee, and the ensuing LinkedIn discussion was passionate (and not necessarily kind to Zigbee).

Emotions and ease-of-use issues aside, the biggest differentiators appear to be range (Zigbee wins) and mesh capability (Zigbee has, Bluetooth doesn’t).

If distance is your issue, then meshing gives you an extra distance bonus, since nodes need only be near each other; the Mother Node or hub or whatever can be much farther away. Traffic will arrive at its destination not through the air in a hub-and-spoke manner, but through the network. The only consideration here is the fact that all of this traffic will be traveling through the nodes, which otherwise would be handling only their own traffic. With a mesh, they also have to route other traffic as well.

So if this sort of configuration is what you need, then it would seem that Zigbee would be the only obvious solution.

Or would it?

CSR has introduced what they call their Smart Mesh. And it’s not Zigbee: it’s built over Bluetooth Smart. Why go through all that effort to do something Bluetooth wasn’t originally designed to do? It goes back to the reason I thought Bluetooth and WiFi were dominating: they’re in smartphones, and Zigbee isn’t.

This adds yet one more wrinkle to the distance scenario above. Yes, if you have a Bluetooth hub, a mesh will give you network reach far beyond what that hub could do on its own. But with the phone, you now have a “mobile hub,” if you wish. As long as you’re in range of one of the nodes, anywhere in the network, the phone can access the network for information or control.

You can find out more about CSR’s specific solution in their announcement.

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Apr 24, 2014

Mentor Unifies Verification

posted by Bryon Moyer

Seems like verification unification is in the air. We saw it recently with Synopsys, and now we have a move from Mentor.

While Synopsys’ version looked like an effort to unify acquired technology, Mentor’s efforts seem more internal. The big picture involves the unification of simulation, formal, emulation, and virtual prototyping under one umbrella, one interface. In that scheme, Mentor presents each of the technologies as an engine serving the higher-level verification goal; no longer is each one of these things a separate tool.

But a big part of what’s happening here is about conjoining emulation and simulation more seamlessly – trying to unify them to a greater extent. We actually looked at Cadence’s version of this some time back, when the verification environment was even more fractured and confusing. But the high-level picture of this relates to making the distinction between simulation and emulation more transparent.

In concept, emulation should just be a faster simulation engine, and you should be able to push the pieces of your design around between the simulator or the emulator – or the virtual prototype – based on what needs to be verified in the greatest detail and how many cycles are required either to run the tests themselves or to support the tests (like getting past the boot-up sequence quickly).

In practice, of course, emulators are hardware, and so only so much of the testbench can move from a virtual environment into real hardware – the so-called synthesizable subset. That requires care on the part of verification engineers to support a flexible testbench, and it’s also the point of new verification IP (VIP) that Mentor has included as a part of this announcement – VIP that transitions more easily between simulation and emulation.

So a big part of what’s new here is in Mentor’s Veloce emulator: their new OS3. And there are several new Veloce capabilities that are important for supporting this unification:

  • It supports a more simulation-like interaction.
  • Assertions can now be synthesized.
  • It now tracks coverage.
  • It supports Mentor’s push to move emulators out of the lab and into the data center for more effective sharing and better machine utilization, including multi-tenanting on a single machine.

Two supporting tools help with this. One is VirtuaLAB, which, somewhat surprisingly, was presented as new, but which we actually saw almost exactly two years ago. This is about eliminating rate matchers when generating “real-world” stimulus for verification. The VirtuaLAB boxes can also go into the data center as general stimulus generators, eliminating the need for someone to be physically present in a lab connecting wires to get data.

The other supporting tool is CodeLink, which we saw quite some time ago. While it’s supported offline simulation debug all the while, it now supports offline emulation debugging and review as well.

There’s actually a subtle consideration here for designs underway on existing Veloce machines. In theory, if you migrate your emulators into a data center and start sharing them on the new OS version, it’s likely this will happen in the middle of some design (it’s impossible to imagine a big company where all projects magically finish at the same time, creating an opportune window for change). The thing is, making changes in the middle of a design project is generally not great for schedule confidence. But Mentor assures us of full backwards compatibility, so that verification plans being executed under older expectations should work just as if nothing had changed.

Meanwhile, they’ve announced a new unified debugger called Visualizer that supports all of the engines, removing the need to move between debuggers when moving between engines.

And, in another trend, simulation results are all stored in a single database, regardless of which engine generated them.

This whole unification movement reflects what’s happening on chips themselves: SoCs now integrate pieces that, in earlier times, would have been created, verified, and debugged separately. And with smaller chunks, you could use separate tools for separate parts of the verification plan. But that’s just not feasible now that every aspect of every circuit has to be known to work properly before cutting an outrageously expensive mask set.

You can get more info in their announcement.

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Apr 22, 2014

Intersil Re-emerges

posted by Bryon Moyer

When you’re musing over Silicon Valley comings and goings over a beer, it’s not unreasonable to hear the question, “Whatever happened to [place company name here]?” And, in some cases, the answer will be, “Oh, they’re still around, they’re just kind of quiet these days.”

Well, that seems to have been the case with a name that’s been around for a long time. If memory serves, they were my first interview as I prepared to move from college to real work. And they’re taking a new initiative to re-establish themselves and their raisons d’être. They’re even referring to it as a re-introduction.

The company in question? Intersil.

They’re calling themselves “A Power Management Company” to articulate what they’re about in a nutshell. They see themselves as leaders in one market, and they’re looking to leverage that into two other important growing markets.

Bucking the mobile incumbents

The one thing that unites mobile applications is the battery. But there’s a catch: Intersil says that optimal battery voltages are in the 3.3-3.5-V range, but that the full battery voltage range, from charged to empty, runs from 2.5 V to 4.5 V. So the converter may have to drop or raise the battery voltage depending on the charge level of the battery. Enter “buck-boost” converters, which can act both as boost (raising) or as buck (dropping) regulators.

The real tricky part is managing the transition from buck to boost and vice versa. For you singers, there’s an interesting analogy. Normally we sing with a “normal” or “chest” voice. Or we can pop up and sing in “head” voice or falsetto. But there’s that point right where the two ranges overlap where you need to transition – even glide – from one to the other. And you don’t want that “yodel” affect (unless you’re yodeling) – you want to move smoothly through it with no one really noticing where the transition happened.

Same thing when moving between buck and boost. And this is, in particular, what Intersil claims to be really good at.

Figure_1_red.png

 

Image courtesy Intersil

RF is another area where they say a very stable yet responsive regulator is needed. They’re even responsive enough to handle envelope tracking, although that will be a future application – if it ever happens (apparently it’s a topic of hot debate, and not really top of mind with Intersil).

They see mobile power challenges growing largely because the SoCs and displays are demanding more power. They see the incumbents in this market as being really good at integration, but that they don’t have the underlying architectures required to excel here. So they’re taking aim at these applications, and they’ve announced new buck-boost regulators (ISL911xx) in this space to get established.

Controlling power digitally

The other skill they claim is digital power, which, ideally, means replacing the analog control parts with digital control (the actual power part is still analog, of course).

But let’s be real here: They don’t just claim digital control as a skill; they say they pretty much invented it around 2005. And that they replace their analog control with digital control, while other companies wrap their analog control with a digital interface.

They see the home for this being big industrial installations, where complex networks of power must be monitored and controlled. With the recent announcement of their ISL8270M/71M family of digital power modules for 25- and 33-amp applications, they say that digital features are now available without a big price barrier.

One of the benefits of a digital approach is realized in what they call their ChargeMode technology. Essentially, given load perturbations – say, aging in the components – they can compensate within a single cycle, replacing any charge missing from the output cap. This involves changing the stability point, which wouldn’t be possible with an analog design. It also helps compensate for transients, keeping the supply nice and steady.

Intersil also provides a design tool to help configure the digital power modules. Think of it as CAD for power: PowerNavigator. It provides a drag-and-drop way of configuring a power system with multiple sources, along with their monitoring and alarm characteristics.

PowerNavigator.png

Click image to enlarge.   Image courtesy Intersil

So with these announcements, Intersil is trying to reinsert itself into the power battle, in particular gunning for markets it doesn’t currently own (mobile and industrial) based on what it knows from the market it currently dominates (personal computing).

You can find out more about their new buck-boost devices here and their new digital control modules here.

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