Audio questions : i2s, dac, oversampling, PIC, FPGA ...

From: yannouch (yann_at_yannouch.net)
Date: 11/30/04 

Date: 30 Nov 2004 09:12:15 -0800

Hello,

I have a board with an embedded PowerPC (mpc8241), on which there is
no audio hardware. I want this board to have audio capabilities. I
have serial ports, usb ... but no i2s, which is, from what I've
understood from my previous readings, the bus needed to control a
DAC.

I'd like the sound data to be oversampled to 192kHz. (let's say I have
a HDD connected to this board and it contains 44.1 kHz PCM data
files.)

Actually my idea is to do smthg like :

MAINBOARD == i2s ==>(OVERSAMPLING?)===> DAC ===> Analog output

with mainboard separated from the rest of the hardware, in order to be
able to plug to it High-Fidelity/High-Quality Audio-DAC

 
So my questions are :

1. Where the oversampling must be done ? in processor ? with a
dedicated hardware ? Before being sent to i2s bus ? after the firts
device (DAC?) on i2s bus ?

2. How can I get this mainboard to have i2s capabilities ? I've
searched a bit, and I think I've understood I should use a dedicated
microcontroller (PIC ? FPGA ?) attached to the main microprocessor.
True ? If I have an i2s bus, can I have the audio DAC separated from
main board, just linking them via the i2s wires ?

3. where can I find some good quality Audio DAC kit, taking data from
i2s bus, sending Analog audio to RCA plugs ?

Thanks

Yann

Relevant Pages

  • Re: Moving From ProTools to Linux? Good or bad?
    ... I find that it's much easier to explain how audio routing works when people know the fundamentals. ... In hardware I always send them to the block diagram, and if necessary, coach them in reading it. ... I get the hint that Jack has something to do with this, but it's just not clear from what I can see from the JACK GUI. ... Has Linux "found" the sound card? ...
    (rec.audio.pro)
  • Re: Tascam US-122 vs. MBox Interfaces
    ... As far as the proc servicing the bus, (or the northbridge, which probably ... has more to do with it than the proc), real-time is real-time is real-time. ... Admittedly, if you push the envelope of the bus's bandwidth, you'll have ... Edirol UA-25 and other audio cards I've used over the years; ...
    (rec.music.makers.guitar.jazz)
  • Re: Good bye
    ... And if you expect a 5-year useful life for hardware, ... windows machines are as stable/reliable as anything running Linux. ... full processor, memory, RF, IF, audio, and peripheral drivers on board. ...
    (Fedora)
  • Re: Not your fathers Applicard
    ... I grew up with audio and have it in my blood. ... of how to put a CPU core on an FPGA, much less the entire Mill card. ... I actually knew this stuff reasonably well when I got my CS degree, but never worked in the hardware domain and it sort of dissipated. ...
    (comp.sys.apple2)
  • Re: Not your fathers Applicard
    ... I grew up with audio and have it in my blood. ... of how to put a CPU core on an FPGA, much less the entire Mill card. ... I actually knew this stuff reasonably well when I got my CS degree, but never worked in the hardware domain and it sort of dissipated. ...
    (comp.sys.apple2)