ARM Community: F1 in Austin, a TVR, a BMW and the Cortex-M0 Webinar - ARM Community

Having moved from the UK to Austin a year ago I was both elated and surprised to hear the announcement last Tuesday that Formula 1 is coming to Austin in 2012. I've always liked fast cars so I couldn't have been more happy. One thing I didn't expect on moving here was to be able to attend a local F1 event. Hot weather, big trucks and rodeo? Check! Expected that. F1?.....Not so much. Although as Austin doesn't currently have a suitable circuit I hope they can get it all sorted in time...

Talking of fast cars, about a year after I joined Acorn Computers as a recent graduate, just around the time my boss Mike Muller was attempting to spin out ARM (it worked out OK), I attended the 1990 Birmingham Motor Show where the star of the show was the newly revealed TVR Griffith. When I saw it I said to myself "I'm going to have one of those when I can afford it". It took me 10 years to afford it, but in August 2000 I took delivery of a purple-blue TVR Griffith 500, the first time in my life I had purchased a brand new car. It was beautiful, but had several short-comings not the least of which was that the exquisitely hand-machined (from solid aluminum) gear shift got almost too hot to touch on a long blast. Additionally the cooling system was almost but not quite adequate for the engine, the chassis was almost but not quite adequate for the power and the build-quality was almost but not quite adequate for a car. It reminds me of a PC I once had before making the switch to a Mac.



One fine Sunday morning in January (a rarity in Cambridge), the day after arriving home from a business trip to Japan I took out the TVR and coming up behind a slow-moving Mercedes decided to overtake. Evidently Mr Mercedes didn't want to go fast but equally didn't want to be overtaken either so just as I pulled level he sped up in an attempt to prevent me from overtaking. Seeing as I had 327 HP under my right foot in a less than one ton car (340bhp per ton power to weight ratio) I was having none it, so I floored it. Unfortunately, even at 50MPH there was more power than traction, and the rear wheels exactly like militant Unite union cabin crew at a BA negotiation got together, held a ballot and voted they didn't have the patience to wait for those up front to make a move. The next thing I knew I had one angry Mercedes driver (who turned out to be a lawyer), $10,000 of damage to my TVR and I don't know how much to the Mercedes.

I was always a little intimidated by the Griffith after that. Frankly 327 HP is more than you need most of the time. In pretty short order I changed it for a new BMW M3 with 343 HP but in a much heavier car (an e46 M3 as we BMW fans know them). It wasn't quite as fast as the TVR but it was more comfortable and practical having rear seats in which a newly acquired baby seat (and matching baby) could fit. But I was never entirely happy with it: the steering wheel was as fat as I imagine the Mercedes-driving lawyer is now and its feel had about as much delicacy.



My next car was an ordinary mid-range BMW 5-series with just 230 HP* (an e60 530i for fellow BMW nerds). It had not only back seats but back doors as well making it easier to live with than the M3. And it was by far the best car I've ever had in my entire life. If I could have brought it with me to Texas I would have. But federal crash-testing regulations put pay to that idea - they haven't crashed one with the steering wheel on that side, and it could be completely different. They'd let me bring it in but they'd have to crash-test it first. Thanks, but no thanks guys. It was too nice a car to crash-test with comfortable seats, an elegant interior, fluid handling, manual transmission, 'just enough' performance, and cost no more to run than a cheap hatchback. It's not the sort of car that small boys stare at like a TVR or an F1 car, it's just not sexy and exciting. But there's good reasons for there being a lot more of them about than TVRs, M3s and F1 cars.

Talking of the M3, in 2004 ARM launched the Cortex-M3 processor to address the market for low-cost microcontrollers. The Cortex-M3 brought 32-bit performance to the $1 microcontroller market for the first time ever. Microcontroller users benefited from the comfort of sophisticated 32-bit development tool chains, the elegant 16/32-bit Thumb-2 instruction set and more performance than the venerable ARM7TDMI could offer. But for some applications that have traditionally been performed by 4 or 8 bit micros or even hardware state machines, it's frankly more than you need most of the time.

Enter the Cortex-M0 launched in 2009. It's the smallest 32-bit processor ever; the name M0 suggests that ARM thinks it will be the smallest for ever more. Just like Austin and unlike Cambridge in winter it really doesn't get much lower than zero (°C). The Cortex-M0 benefits from the same comfortable 32-bit tool-chain environment, with just one AMBA AHB master interface it's easier to live with than the M3, yet is just as small and taking into account memory requirements is even lower cost to run than 8-bit micros. For many applications it has 'just enough' performance and it's simple enough to be unintimidating for even the most inexperienced of designers. It may not be sexy or exciting, small boys won't stare, but just like mid-range BMWs and the ARM7TDMI there's going to be a lot of them around and for good reasons. Plus, it won't overheat like a Mercedes McLaren F1 car with the radiator cover left in or a TVR with the engine left running too long.

I learnt the hard way: More performance isn't always better. You can learn it too without having to crash a car by attending our Cortex-M0 webinar presented by my current boss Bryan Lawrence who's not (as far as I'm aware) attempting to spin out anything; except perhaps the wheels of one of his two Minis, an old one set up for the track and a new (made by BMW) Mini for the road.

This weekend it was Turkey. As expected Jenson did rather better with the McLaren radiator cover off coming in second behind team-mate Lewis Hamilton in the other McLaren. But it was the Red Bull cars that were the big story of the weekend. Somehow, rather like McLaren Mercedes and the radiator cover, and me and the Mercedes-driving lawyer I don't think Webber and Vettel will make that mistake again. But it's the 2012 Formula 1 season and the Austin GP I'm really looking forward to.

* Those following the Wikipedia link will see that it says the e60 530i had 255 HP but what it doesn't tell you is that the early e60 530i models (which mine was) had the e39 530i engine

Ashley Stevens, Solutions Architect, ARM, helps customers deploy the latest ARM products and technologies to create innovative holistic system solutions. He's been with ARM since 1995 and has a background in SoC design and architecture, working for seven years in ARM design services. Previously he worked for Acorn Computers where the ARM processor was originally developed, Tadpole a maker of Unix laptops, and Marconi. Ashley holds a Bachelor of Engineering in Computer Engineering from Queen Mary College London.

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