[sdiy] Proposed DSP board

[Scott Gravenhorst]

Neil Johnson <neil.johnson97 at ntlworld.com> wrote:
>Hi,
>
>Scott Gravenhorst wrote: 
>> >FPGA is good for parallelizable algorithms, and where the design is mostly
>> > fixed. 
>> 
>> Can you explain what you mean by "mostly fixed" ?
>
>*My* definition (yours may vary) is where the usual FPGA 
>stop-the-world-and-reload-the-bitstream implies some level of 
>'fixed'. *Some* DSPs can load modified/different code at runtime 
>so there is no penalty to update the system when live. For 
>example, loading a bugfixed MP3 codec while decoding a JPEG image 
>or rendering a MIDI file. 
>
>Of course, if you're into modifying the FPGA configuration after 
>the initial bitstream load then this is not so much an issue, 
>other than the limitations of what you can modify without 
>affecting the 'live' parts of the FPGA - you can go down routes 
>of locking parts of the design during P-n-R so that config 
>updates don't mess with live parts of the FPGA (and by 'live' I 
>mean those parts of the FPGA that are currently handling data at 
>the time the update takes place). 

My concern was that there might be members considering using FPGAs as synthesizers taking
that to mean once it's programmed, it's done or difficult to change.  Sure, once the horse
is halfway across the river, it's not the time to change it's shoe, but being based on
static RAM, and FPGA can be reloaded as often as one needs.  So in that respect, it's
anything but fixed.

>Bringing this back somewhere near the topic, I think this thread 
>is an excellent example of what happens when you ask on-list what 
>features a module should have! A thousand eyes, a million 
>opinions. Entertaining at the very least. 
>
>For Tim, I'd suggest do whatever you want that makes it 
>interesting for you. You'll never design a board that meets 
>everyone's requirements. This is synth-diy - whatever you do, do 
>it because its fun! 
>
>I leave it as an exercise for the reader to define "fun".
>
>Cheers,
>Neil
>--
>http://www.njohnson.co.uk
>

-- ScottG
________________________________________________________________________
-- Scott Gravenhorst
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