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Old standards never die

paulmcl — Mon, 14 Nov 2011 02:32:56 +0000

I just put up a blog about the EDA interoperability forum, much of which is focused on standards. Which reminded me just how long-lived some standards turn out to be.

Back in the late 1970s Calma shipped workstations (actually re-badged Data General minicomputers) with a graphic display. That was how layout was done. It’s also why, before time-based licenses, EDA had a hardware business model, but that’s a story for another day. The disk wasn’t big enough to hold all the active designs, so the typical mode of operation was to keep your design on magnetic tape when you weren’t actually using the system. Plus you could use a different system next time rather than having to get back on the same system (this was pre-ethernet). The Calma system was called the graphic design system and the second generation was (surprise) labeled with a two. That tape backup format was thus called “graphic design system 2 stream format”. Or more concisely GDS2. Even today it is the most common format for moving physical layout design data between systems or to mask-makers, over 30 years
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On-chip supercomputers, AMBA 4, Coore’s law

paulmcl — Tue, 12 Jul 2011 14:42:27 +0000

At DAC I talked with Mike Dimelow of ARM about the latest upcoming revision to the AMBA bus standards, AMBA 4. The standard gets an upgrade about every 5 years. The original ARM in 1992 ran at 10MIPS with a 20MHz clock. The first AMBA bus was a standard way to link the processor to memories (through the ARM system bus ASB) and to peripherals (through the ARM peripheral bus APB). Next year ARM-bsed chips will run at 2.5Ghz and deliver 7000 MIPS.

Eric’s story of Thomson-CSF’s attempt to build a processor of this type of performance in 1987 points out that in those days that would have qualified as a supercomputer.

The latest AMBA standard proposal actually steals a lot of ideas from the supercomputer world. One of the biggest problems with multi-core computing once you get a lot of cores is the fact that each core has its own cache and when the same memory line is cached in more than one place they need to be kept coherent. The simplest way to do this, which works fine for a small number of cores, is to keep the line in only one cache and invalidate it in all the others. Each cache monitors the address lines for any writes and invalidates its own copy, known as snooping. As the number of cores creeps up this become unwieldy and is a major performance hit as more and more memory accesses turn out to be to invalidated lines that therefore require an off-chip memory access (or perhaps another level cache, but much slower either way). The problem is further compounded by peripherals, such as graphics processors, that access memory too.

Intel buys an ARMy?

paulmcl — Tue, 19 Apr 2011 22:31:52 +0000

Is Intel in trouble? Since it is the #1 semiconductor company and, shipping 22nm in Q4 this year with 14nm in 2013, it is two process generations ahead of everyone else it is hard to see why it would be. Intel, of course, continues to dominate the market for chips for notebooks, desktops and servers. But therein lies the problem. Pads are killing netbooks and nibbling at notebooks. These are not growing markets and actually are starting to gradually shrink. Instat reckons that in Q1 2011 PC volumes are down 2-3% from Q1 2010, largely due to incursion of iPads.

The growing markets are largely ARM-based: smartphones and iPad type computers. Intel’s approach to these markets has not been a success. First, after its acquisition of (part of) Digital’s semiconductor business it got StrongARM, renamed it Xscale, and invested something like a billion dollars in trying to penetrate the communications business. Eventually it disposed of that business to Marvell in a fire sale. Depending on what residual rights they retained this could turn out to have been an enormous strategic error. They didn’t just give up a ARM manufacturing license, they gave up a do-pretty-much-anything ARM architectural license.

DesignCon

paulmcl — Thu, 03 Feb 2011 16:34:16 +0000

I spent Tuesday at DesignCon. I expected more EDA participation. All the big guys were there with skeleton crews and a few middle sized guys but they were outnumbered by all sorts of companies that are peripheral to design. How many companies making various forms of connectors are there?

It turned out one of the most interesting things was a lunch meeting with Tyco Electronics. To be honest, I only went because they provided somewhere to sit and a free lunch. They were announcing some new technology around RJ-45 (the plug of the internet, that you plug wired ethernet into). I had no idea that…read more