For hardware engineer types re: sound controlers and/or codec chips ??

[john wendel]

On 09/05/2009 10:36 AM, William Case wrote:
> Hi;
>
> I am chasing down the creation or production of sound on my computer.
> Everything is fitting into place after being at it, on and off, for a
> couple of years.  However, there is one hardware answer I don't seem
> able to chase down.
>
> Where is the sound data kept immediately on arrival at the sound card?
>
> Whether analog or digital; whatever the source; sound arrives at the
> sound card or at on-board chip(s).  Whether the sound is in 'chunks',
> 'segments' or 'packets',  the sound data has to be stored somewhere on
> the sound card, before being coded or decoded, or before being moved to
> the DMA.
>
> I expect that the memory requirements are small, perhaps only a few
> bytes, but none-the-less, the sound card has to (I would think) store
> the data somewhere before processing it and putting it in a DMA buffer.
>
> Is my assumption about temporary, perhaps 1-2 ticks, storage accurate?
>
> Where is this data stored?
>
> Does the sound card itself have some small capacity for memory?
> -- SRAM or DRAM?
>
> If so, is this storage a property or function of the sound controller or
> the codec chip?
>
> Is there a way to tell the size or nature of this memory from the
> specifications, or, the hardware definitions in lshw, or,
> cat /proc/asound/card*/pcm*/info?
>
> Is, for some reason, this information propitiatory to manufacturers ?
>
> If it is propitiatory, can you give me a best guess?
>
> In the end, this is not a terribly important issue, other than without
> an explanation, the understanding of the logic chain for hardware and
> software used by sound is broken.
>
>

Take a look here...

http://www.intel.com/design/chipsets/hdaudio.htm

Regards,

John