[sdiy] The magic of ARM

[Byron G. Jacquot]

>>> This may be going to far afield, but I am curious: what is it about the ARM designs in particular that has led to that architecture becoming so completely dominant, vs., say MIPS or whatever?
>> 
>> ARM has a very interesting licensing scheme. Instead of huge down-payments plus per-item royalties like the others they pretty much license on a per-item base.
>
>Very interesting! So it's not that ARM is *technically superior* to MIPS, or AVR32, etc? They basically nailed a better business model? 
>

ARM became a defacto standard by licensing their IP to many vendors.  They don't sell silicon - they sell the recipe for the silicon.  And rather then invest in from-scratch R&D, many vendors opted to license the core.  It also coincides with the cell phone revolution...a lot of demand for chips like that.

As developers, we can get similar processors from several vendors, with the reasonable expectation that the related tools (compiler, debugger, etc) are compatible.

The internals of the processors are also pretty good.  Orthogonal RISC instruction set, options for low power modes, and modularity for the big-gun features (hardware multiply, floating point, memory controller, DMA, etc).  The architecture scales across broad ranges of processing power and dissipated power.

-Byron Jacquot