New DRAM Interfaces Keep Memory Buses Humming
A pair of new DRAM interfaces broke cover recently, and both promise to make engineers’ lives tougher – no, wait, easier! Sorry. Easier because the new interfaces make memory faster and more power-efficient (both good things), but tougher because it’ll be harder to decide which one you want. And they’re definitely mutually exclusive.
One interface comes from the Hybrid Memory Cube Consortium, a nonprofit group of DRAM makers and DRAM users (that’s a large group) that collectively work on defining how hybrid memory cubes should work. The other comes from Rambus, the decidedly for-profit company that makes its business developing and licensing interface-related IP.
Fish Fry is getting down to bare metal. We’re talking the who, what, where, and how of multi-substrate technology and checking out why the tools of today may not be up to snuff for tomorrow’s 3D IC packaging. Also this week, we look at the challenges of 100G designs and investigate why Portland, Oregon was ranked the second nerdiest city in the United States.
Cadence Rolls Sigrity and Allegro - Together
Board design and layout used to be so simple. All you had to do was make sure that all the metal parts that were supposed to touch did, and all the metal parts that were not supposed to touch didn't. Handy software tools did all the heavy lifting, and there were about a zillion different possible layout solutions - all of which worked.
That was back in the day - before all this high-speed serial nonsense. Now, thanks to our multi-gigabit lifestyle, just making the metal touch doesn't cut it anymore. We have to worry about signal integrity (SI). All those zeroes and ones flying through PCB traces start to cut corners, and our eyes slowly begin to close…
Altium Alters Course
Altium has long been a standout in the EDA industry. The company got its start as Protel - a supplier of affordable desktop PCB layout solutions. When the big EDA suppliers were exclusively selling expensive, workstation-based, enterprise-level board design systems, Altium (Protel) provided a strong, usable desktop solution for everybody else - the people who didn’t have a huge design tool budget.
As Protel evolved into Altium, their differences from the pack became more pronounced. Altium became the company of vision, with the goal of supplying the masses with a comprehensive tool suite including design capture, FPGA design, embedded software development, and trusty-old board layout. They wanted to give you an affordable desktop solution that could take your product design from soup to nuts, as long as you weren’t doing custom IC design.
Alta Devices Changes the Rules
Batteries are the bane of portable device design.
Just about every portable or mobile device or system that does anything interesting - that is, anything that would require a “real” chip like a processor or FPGA, or anything that does meaningful real-world interaction like drive a display or spin a motor - needs a significant amount of power. When you can’t plug into the wall or the grid, your options are pretty narrow. The essence of your design becomes a tradeoff between the capability and longevity of your device and battery size, weight, and cost.
We’ve all briefly considered solar, of course. The romantic idea of a perpetually powered system gleaning what it needs from nothing more than the ambient light is a powerful aphrodisiac. We want to go on a date with solar. We buy flowers. We show up at solar’s door in our spiffiest engineering outfit.
TI OMAP applications processors are powerful and flexible; this makes them well suited for navigating difficult power and thermal constraints. However, the complexity of OMAP parts is high and the ways in which to use them are varied and intricate. This article focuses specifically on ways to improve thermal performance in TI OMAP parts that limit the source of heat in integrated circuits: power. Before getting into specifics about how to manage thermal problems with OMAP, let’s remember that to manage thermal issues, there are three approaches we can take.
The Importance of Fun Projects in Engineering
Most little kids want to grow up to be cowboys, ballerinas, astronauts, or firemen. Not you. You wanted to be an engineer, didn’t you? You wanted to make stuff.
I’m willing bet you didn’t become an engineer or a programmer by accident. You chose that career. You weren’t born into it. You probably didn’t inherit your father’s engineering practice. Your family doesn’t come from a long line of engineers that expected you to uphold the family tradition. You weren’t assigned to Job Classification 35.984.001 by an immense and bureaucratic government agency.
You’re an engineer because you like it.
Considering EDA Tool Longevity
There is a story in the American South about two “country boys” who walk into a lumber yard and ask to buy some wood. The lumber yard attendant asks what size they want. They look confused. He gives them some choices “two-by-fours, two-by-sixes, four-by-fours...”
They step aside for a minute to confer with each other. “We’ll take two-by-fours.”
The lumber yard attendant takes them to the aisle with the two-by-fours. “How long do you need them?”
This week’s Fish Fry is all about those persistent pesky power problems that plague our designs and what we can do to solve them. If you’re a digital guy or gal struggling to get into the analog game, or even if you’re an analog person trying your hand at digital design, this Fish Fry is for you. First, I interview Steve Logan (Xilinx) about how Xilinx has added analog ADCs to their recent development kits and how you can start designing with one. I also chat with Rob Chiacchia (Linear Technology) about the state of the art in digital power management.
(and Some Good Tools)
PCB problems got you all tangled up and blue? Never fear, all you need is love. Well, that and some good tools. This week my guest is Steve McKinney (Mentor Graphics). Steve and I are going to talk to about Mentor’s HyperLynx tool suite and why the newest features of this tool may make those pesky PCB problems a thing of the past. Also this week, check out why power and system management decisions might best be made sooner than later.
Mentor HyperLynx Helps Handle the Hot Spots
Is it just me, or is digital design getting a lot trickier? We were all going along just fine, flipping our little zeroes and ones happily back and forth, and then somebody comes up with the brilliant idea to replace our nice, simple parallel busses with serial IO. OK, so maybe those parallel busses were not quite so simple by that time; it was starting to be nearly impossible to do the board layout so that all those signals arrived at somewhat the same time. To make matters worse, we kept raising the clock frequencies until “somewhat the same time” wasn’t even close to good enough anymore.
Fish Fry Takes On DesignCon
Eye diagrams, Bert Scopes and more SerDes than anyone knows what to do with...what could it be? DesignCon of course. In this week’s Fish Fry, I look into to why DesignCon was so popular this year and why signal integrity issues were the un-offcial theme of the show. I also interview Brad Griffin of Cadence about why we need power distribution analysis and why he thinks DesignCon is the best show of the year.
Where Green Pastures End
Just about every electronic technology on the market today has alternatives. Between custom chips, ASSPs, pre-built modules, embedded processors, microcontrollers, FPGAs, and a host of other silicon-based goodies, there are always numerous ways to solve any given problem. As engineers, we make our choice based on any number of criteria - cost, power, size, reliability, our familiarity and experience with the technology, our company’s preferences... all of them weigh into our decision.
Zuken Redesigns their Board Tools from Scratch
Anyone who’s ever done any serious remodeling of their home knows the big decision. At some point, wouldn’t it really be easier just to mow down the existing structure and start over?
Little by little, as you add new ideas – “while you guys are at it” – the costs mount, and that’s even without considering the surprises that are inevitably encountered. And if you go from a two-dimensional home – one story – and add a third dimension, it gets crazier. Most single-story homes aren’t built strong enough to support a second story. So you end up doing things like building a separate support framework to hold up the new top floor or, even more crazily, hoisting the original house up to make it the top floor and then building a new first floor under it. (Yes, people do this.)
Hoover Dam is pretty damn impressive. Why, some might simply say it’s a pretty dam.
As you take the tour, much is said about its size, the effort to build it, the clever techniques used to cool the concrete, and, if you’re lucky, the volume of water rumbling through the penstocks inches below the ominously vibrating surface you’re standing on.