Apr 25, 2013

ThreadX Gets Safety Certification

posted by Jim Turley

San Diego-based Express Logic just received IEC 61508 and IEC 62304 certification for its ThreadX operating system. These two standards cover the "functional safety of electrical, electronic, and programmable electronic safety-related systems." The nice part is, the certification is for bone-standard ThreadX; there is no special "safety-certified" version of the RTOS. Express Logic says it won't even charge more, now that it's certified.

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Apr 25, 2013

An Acid Trip

posted by Bryon Moyer

When you think of a high-acid environment, what do you think of? That can of soda? Lemon juice? Your stomach? Battery acid? Well, to review, neutral pH is 7. Your stomach will have a pH of 1.5 to 3.5, presumably depending on how much soda or lemon juice or Thai-spicy tom yum gai you just had. Coca-Cola Classic is around 2.5. Lemon juice: 2.0. Battery acid: 1. It’s hard to imagine electronics functioning in a bath of any of those tongue ticklers.

But there’s an environment that’s even worse. One within which an electronic component must operate. And you might never expect it. In fact, many folks didn’t expect it. It can have a pH of 0.5 or less. It’s car exhaust. And it’s not all gaseous. It can make mincemeat of your chip in a couple months. Who knew…

Certainly not the many folks trying to build pressure sensors for that environment. Sensata has just announced a relative pressure sensor for this application – and even they didn’t realize this when they started.

There are actually a couple things that they’ve done that others have had trouble with. One is simply getting this to work in such an environment; the other is doing it with a single element – other folks apparently use two pressure sensing elements (and measure the difference between them).

The Sensata approach is a two-port sensor, with one sealed port on each side of a piezo-resistive element. Each port exposes the pressure of one of the environments to be compared, so the element is, by definition, providing the relative pressure difference. The element, which, of course, has a backside etch so the membrane is accessible to front and back, is mounted in a ceramic carrier.

Then there’s the bit about the acid. There are lots of things that can be attacked, most of which are on the logic that makes sense out of the raw pressure measurement. In other words, CMOS. Much of it can be protected by suitable passivation, but you still have to get the signals in and out, and that takes metal. And, no matter how much you protect everything else, that metal isn’t going to like lots of acid.

So rather than having that logic on the same chip as the element or an ASIC collocated with the element, they put the ASIC away from the element, outside of the corrosive environment. That minimizes the part that has to be robust and protects the delicate bits.

You can find more in their release

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Apr 24, 2013

Continued FinFET Roll

posted by Bryon Moyer

The Synopsys Users’ Group scheduled a panel session on FinFETs at their recent session. This is consistent with pretty much every EDA company providing FinFET content for their users; they’re the latest hot topic, and represent a non-trivial change.

But the popularity of the topic was driven home rather starkly. They used the auditorium at the Santa Clara Convention Center, and even so, it was standing-room only, and many, many people had to be turned away when there wasn’t more room for standing. So interest was obviously quite keen. Which reflect the fact that FinFETs are in transition: once the far-out concept for some future technology node, this stuff is becoming real for lots of real engineers.

And, for the most part, the panel said the usual things you might expect about why FinFETs are necessary or good and what’s different about using them. The Synopsys speaker talked about the tools, of course, but it was still too early to see the results of the lead lots they had put through.

And it was refreshing to have Cavium on the panel as a user, with the candor to discuss what they felt was the biggest drawback about FinFETs: parasitic capacitances. As in, there are too many of them. So they were having trouble keeping dynamic power down. They requested EDA help both in optimizing dynamic power consumption and with EM analysis.

Not that they thought that FinFETs were a bad idea in general; they agreed with the litany of benefits that is typically trotted out. But their willingness to say, “They’re good but…” helped give a real-world feel to the kind of panel that can too often be simply an echo chamber for laudatory talking points.

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