[sdiy] STM32 processor

[Eric Brombaugh]

On 09/15/2011 10:41 AM, Olivier Gillet wrote:
> Has anybody tried to benchmark those (esp. the 72 MHz parts) against
> dsPICs for audio generation or audio effects? I'm curious to know
> whether 40 Mhz clock + 16 bits instruction set with DSP features can
> beat 72 Mhz clock (with wait states from the flash) + generic 32 bits
> instruction set.

That was part of the rationale behind my experiment with the 'F100 part 
- to see how it compares with the dsPICs I've used previously. Although 
this one is running at just 24MHz compared to the 40MHz that the dsPIC 
runs (no waits in either), I found that the 32-bit native register 
operations provided a 'force multiplier' effect that erased some of the 
difference in cycle speed. The interpolated wavetable oscillator 
algorithms compare quite favorably running on the two different 
architectures.

The dsPIC does have an advantage in providing true DSP capabilities 
though - zero-overhead looping hardware, dual operand buses with 
parallel address calculations and true single-cycle MAC instructions 
that greatly accelerate filters, interpolations, etc. The ARM 
architecture won't be able to match that without a behind-the-scenes 
overhaul which even the newer Cortex-M4 series doesn't really provide 
based on my reading of the documentation.

Eric