Desktop Board Description
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1.9 Audio Subsystem
The board includes an Audio Codec ’97 (AC ’97) compatible audio subsystem consisting of these
devices:
•
Intel 82801BA ICH2 digital controller (AC link output)
•
Analog Devices AD1885 analog codec
Features of the audio subsystem include:
•
Split digital/analog architecture for improved S/N (signal-to-noise) ratio:
≥
85 dB
•
3-D stereo enhancement
•
Power management support for APM 1.2 and ACPI 2.0 (driver dependent)
The audio subsystem supports the following audio connectors:
•
Inputs:
Three analog line-level stereo inputs for connection from line in, CD, and auxiliary line in
One mono microphone input
•
Output: Stereo line-level output
For information about
Refer to
Obtaining audio software and utilities
Section 1.2, page 16
Obtaining the AC ’97 specification
Table 3, page 16
1.9.1 AD1885 Analog Codec
The AD1885 is a fully AC ’97 compliant codec. The codec’s features include:
•
> 90 dB signal-to-noise ratio sound quality
•
Power management support for APM 1.2 and ACPI 2.0 (driver dependent)
•
Playback sample rates up to 48 kHz
•
16 bit stereo full-duplex operation
•
Software compatible with Windows
†
98 SE, Windows 2000, Windows Millennium Edition
(Windows Me), and Windows NT
†
4.0
•
Full-duplex operation at asynchronous hardware record/playback sample rates
•
Frequency response: 20 Hz to 20 kHz (
±
0.1 dB)
Figure 4 is a block diagram of the board’s audio subsystem, including the Intel 82801BA ICH2
digital controller, the AD1885 analog codec, and the audio connectors.
82801BA
I/O Controller Hub
(ICH2)
OM11133
CD-ROM
Auxiliary Line In
Mic In
Line In
Line Out
Analog Devices
AD1885
Analog Codec
AC ’97 Link
Figure 4. Block Diagram of Audio Subsystem
