39
005- net rsb<0>
loc=p59;
006- net rsb<1>
loc=p57;
007- net rsb<2>
loc=p51;
008- net rsb<3>
loc=p56;
009- net rsb<4>
loc=p50;
010- net rsb<5>
loc=p58;
011- net rsb<6>
loc=p60;
012- net db<1>
loc=p41;
013- net db<2>
loc=p40;
014- net db<3>
loc=p39;
015- net db<4>
loc=p38;
016- net db<5>
loc=p35;
017- net db<6>
loc=p81;
018- net db<7>
loc=p80;
019- net db<8>
loc=p10;
•
Listing 22:
XS95 UCF file for the PS/2 keyboard interface.
001- net rst
loc=p45;
002- net oeb
loc=p62;
003- net kb_data
loc=p70;
004- net kb_clk
loc=p26;
005- net rsb<0>
loc=p58;
006- net rsb<1>
loc=p56;
007- net rsb<2>
loc=p54;
008- net rsb<3>
loc=p55;
009- net rsb<4>
loc=p53;
010- net rsb<5>
loc=p57;
011- net rsb<6>
loc=p61;
012- net db<1>
loc=p44;
013- net db<2>
loc=p43;
014- net db<3>
loc=p41;
015- net db<4>
loc=p40;
016- net db<5>
loc=p39;
017- net db<6>
loc=p37;
018- net db<7>
loc=p36;
019- net db<8>
loc=p35;
Inputting and Outputting Stereo Signals Through the Codec
The stereo codec on the XStend Board is capable of digitizing two analog signals to 20
bits of resolution while simultaneously generating two analog signals from 20-bit values. A
high-level view of the codec chip is shown on the right-half of
Figure 11
. Two analog
inputs (which are typically the left and right channels of a stereo audio signal) enter the
codec and are digitized into two 20-bit values by analog-to-digital converters (ADCs).
These values are loaded into shift registers, which are shifted out of a single pin of the
codec under control of a shift clock and a left/right channel selector control input. At the
same time, 20-bit values are alternately shifted into two shift registers in the codec, which
feed digital-to-analog converters (DACs) that drive two analog outputs. Signals on these
outputs are typically the left and right channels of a stereo audio signal.
Summary of Contents for XStend XS40
Page 17: ...16 Figure 5 Programmer s model of the XS40 XStend Board combination...
Page 18: ...17...
Page 20: ......
Page 31: ......
Page 33: ......
Page 41: ......
Page 58: ...Appendix A XStend Schematics...
Page 59: ...XStend V1 3 XS Board Connectors...
Page 60: ...XStend V1 3 RAM...
Page 61: ......
Page 62: ...XStend V1 3 Stereo Codec...
Page 63: ......