This is a simple design example that digitizes a stereo audio input and then converts
it back into an audio output (i.e., a simple audio loopback).
- common.vhd
This file contains some definitions and functions used in the rest of the VHDL code.
- audio.vhd
This is the VHDL file that describes an interface to the stereo audio codec and then uses this
interface to digitize a stereo input waveform and then convert it back into an analog output.
You can get a more detailed description of the codec interface at http://www.xess.com/appnotes/an-032904-codec.pdf .
- audio.ucf
These are the constraints which assign the I/O signals of the stereo codec interface to the
appropriate pins of the FPGA on the XSA-3S1000 + XST-3.0 combination.
- audio.bit
This is a compiled bitstream for the design that can be downloaded into the XSA-3S1000 + XST-3.0 combination.
- audio-200.ucf
This is an alternate set of pin assignments to be used if the design is recompiled for
an XSA-200 + XST-3.0 combination.
- audio.npl
Open this project file with WebPACK if you need to recompile the design.
- Step 1:
Set jumper J9 on the XSA-3S1000 Board to XS.
- Step 2:
Download the default parallel port interface into the XSA-3S1000 (\XSTOOLS\XSA\3S1000\dwnldpar.svf)
if it is not already present. (Running GXSTEST will do this automatically.)
- Step 3:
Connect a stereo cable from the line-out of a PC audio card to the J1 (IN) jack of the XST-3.0 Board.
Connect stereo headphones to the J2 (OUT) jack.
On the XST-3.0 Board near the audio jacks, make sure the shunts are removed from jumpers JP2 and JP3 and
placed on jumpers JP4 and JP5.
- Step 4:
Download the audio.bit file to the XSA Board.
- Step 5:
Use Windows Media Player to play a .wav file from the \WINDOWS\Media folder. The sound should be output
through the headphones.
Hold down pushbutton PB1 on the XST-3.0 Board to keep the circuit in the FPGA in its reset state.
No sound should come from the headphones while the circuit is in the reset state.
This example design was developed using the following version of software:
Xilinx WebPACK : 6.3.03i
You can download the source files for this example design from the XESS website at
http://www.xess.com/projects/xst3_audio.zip .
Dave Vanden Bout, X Engineering Software Systems Corp.
Send bug reports to bugs@xess.com.
Copyright 2006 by X Engineering Software Systems Corporation.
This application can be freely distributed and modified
as long as you do not remove the attributions to the author or his employer.
01/29/2006 - Initial release.