[sdiy] Quality reverb on STM32's?

[Richie Burnett]

Exactly what Eric said.  The FV-1 instruction set is specifically optimised for the job of chorus / flange and modulated reverb processing. It is most definitely not suited to many things that you might normally take for granted on a typical DSP. Processing audio in blocks of samples, for example.

As for the dsPIC, I find it very similar to analog devices' original 16-bit fixed point ADSP2181 DSP. Someone once described PICs to me as "almost a decent microcontroller", (...except for things like the quirky paged program memory, banked RAM etc.) In a similar way i'd describe dsPIC as "almost a decent DSP." I've used them in many commercial projects and they hit a certain price/performance point, but they have limitations, and are no TMS320 or SHARC.

I've got an ADSP21469 4th gen SHARC board here on my desk and it is a flying machine in terms of processing power, I/O bandwidth and flexibility compared to dspic. But they are in different price and complexity brackets of course. 

-Richie,

Sent from my Xperia SP on O2

---- Eric Brombaugh wrote ----

>On 04/14/2018 12:23 PM, rsdio at audiobanshee.com wrote:
>> 
>> The FV-1 has a DSP at its core. It seems entirely unlikely that it has an instruction set that is any more optimized for reverb than other modern DSP options.
>
>Take a close look at the FV-1 ISA:
>
>http://www.spinsemi.com/Products/datasheets/spn1001-dev/SPINAsmUserManual.pdf
>
>* There are single op instructions specifically constructed to compute 
>all-pass filters and LFOs.
>
>* There are built-in exponential and sinusoid lookup instructions.
>
>* The memory architecture has been designed with a built-in 
>auto-incrementing offset pointer that allows construction of delay line 
>circular buffers with implicit pointer updates.
>
>* The buffer memory is a quirky kind of floating point that's specially 
>designed for handling audio.
>
>Granted - you can do all these things with a few instructions in a 
>standard DSP from ADI, TI or MCHP, but they haven't been quite so 
>strongly focused on reverb applications.
>
>Eric
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