Arduino Goes ARM

mikejuk writes "The whole world seems to be going in ARM's direction. The latest version of Windows 8 will run on ARM processors, Raspberry Pi is a $25 ARM based machine and now the open source Arduino platform has a new member — the ARM-based Arduino Due announced at the Maker Faire in New York. The Due makes use of Atmel's SAM3U ARM-based process, which supports 32-bit instructions and runs at 96Mhz. The Due will have 256KB of Flash, 50KB of SRAM, five SPI buses, two I2C interfaces, five serial ports, 16 12-bit analog inputs and more. This is much more powerful than the current Uno or Mega. However, it's not all gain — the 3.3V operating voltage and the different I/O ports are going to create some compatibility problems. Perhaps Intel should start to worry about the lower end of the processor world."

Re:"Should start to worry"?

[dbc]

Sure, and Intel has been worrying for over 15 years. But here is the thing... the #1 thing that matters at Intel is gross margin per wafer. Intel fills its fabs, and runs them throttle to the firewall 24x7. Every project is ranked by gross margin per wafer... fall below the cut-off line, and you either buy fab from somebody like TSMC, or go find a different project to work on. The Intel Atom is a successful attempt to create a power efficient part that meets the gross margin per wafer test. Go look at the margins of the ARM makers. I'll bet it doesn't match Intel's.

I overheard a very interesting+insightful conversation among vendors at the ARMTech conference a year or so ago. "We are all just vendors of value-added flash. Look at the die photos. It's a whole lot of flash memory, with a little bit of logic around the margins for a processor and peripherals in order to differentiate our flash from the other guys' flash and add some value."

Intel is doing what makes business sense for Intel. But they are watching. And Intel, big as it is, can turn on a dime, and has enough fab capacity to pave over with silicon any competitor that gets in it's boresight. That said, in the space where I work (embedded) ARM is taking over the world. It really makes zero sense to use an 8 bit uCtlr just about anywhere anymore, when you can get an ARM in the same size package and at nearly the same cost. Since flash dominates the die area in a microcontroller, 8-bit versus 32-bit logic is noise -- it has less cost impact than the package. There are a lot of Cortex-M3 parts in 48 pin packages now that cost only slightly more than 8 bit parts. (I should point out that there is huge difference between, an ARM Cortex-M3 and an ARM-A9, for instance an MMU.)

In the end, it comes down to MIPS and MFLOPS, and the die area and power required to do that much computation. When an ARM has enough functional units to match the MIPS and MFLOPS of an x86, it will take as much die area and power. At the complexity level of a Pentium IV, the added ugliness of the X86 instruction set is pretty much noise in the total die area and power. (In a past life I was an instruction decode and pipeline control logic design specialist -- I can tell you that x86 instruction decode is as ugly as it comes -- and in the day and age of out-of-order execution, that almost doesn't matter, except that because of all that ugliness x86 code is freakishly dense, which means the same size I-cache holds a lot more useful code. When you toss in the fact that the ugliness is also guarantees employment for instruction decode specialists, I'd call that a win :)