XESS XStend XS40, Manual

Page: 13 / 63

12
Stereo Codec
The XStend Board has a stereo codec that accepts two analog input channels from jack
J9, digitizes the analog values, and sends the digital values to the XS Board as a serial bit
stream. The codec also accepts a serial bit stream from the XS Board and converts it into
two analog output signals, which exit the XStend Board through jack J10.
The codec is configured by placing shunts on the jumpers as indicated in Table 2 .
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Table 2: Jumper settings for XStend codec.
Jumper Setting
J11 Placing a shunt on this jumper disables the codec by holding it in the reset state. No shunt should be placed
on this jumper when the codec is being used.
J17 Removing this shunt prevents the codec’s serial data output from reaching the XS Board. A shunt should be
placed on this jumper when the codec is being used.
Listing 11 and Listing 12 show the connections from the XS40 Board to the codec
interface on the XStend Board (expressed as UCF constraints):
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Listing 11: Connections between the XStend stereo codec and the XS40 Board.
# STEREO CODEC CONNECTIONS
NET MCLK LOC=P9; # MASTER CLOCK TO CODEC
NET LRCK LOC=P66; # LEFT/RIGHT CODEC CHANNEL SELECT
NET SCLK LOC=P77; # SERIAL DATA CLOCK
NET SDOUT LOC=P6; # SERIAL DATA OUTPUT FROM CODEC
NET SDIN LOC=P70; # SERIAL DATA INPUT TO CODEC
NET CCLK LOC=P44; # CONTROL SIGNAL CLOCK
NET CDIN LOC=P45; # SERIAL CONTROL INPUT TO CODEC
NET CSB LOC=P46; # SERIAL CONTROL CHIP SELECT
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Listing 12: Connections between the XStend stereo codec and the XS95 Board.
# STEREO CODEC CONNECTIONS
NET MCLK LOC=P11; # MASTER CLOCK TO CODEC
NET LRCK LOC=P5; # LEFT/RIGHT CODEC CHANNEL SELECT
NET SCLK LOC=P72; # SERIAL DATA CLOCK
NET SDOUT LOC=P66; # SERIAL DATA OUTPUT FROM CODEC
NET SDIN LOC=P71; # SERIAL DATA INPUT TO CODEC
NET CCLK LOC=P46; # CONTROL SIGNAL CLOCK
NET CDIN LOC=P47; # SERIAL CONTROL INPUT TO CODEC
NET CSB LOC=P48; # SERIAL CONTROL CHIP SELECT
The analog stereo input and output signals enter and exit the XStend Board through the
1/8” jacks J9 and J10, respectively. The output of an audio CD player can be input
through J9 and a set of small stereo headphones can be connected to J10 for listening to
the processed output.
The digitized data output from the codec passes through jumper J17 on its way to the XS
Board inserted in the XStend Board. A shunt should be placed on J17 when the codec is
being used. Because the serial data output of the codec is not tristatable and because it