HP Compaq d330 DT User Manual

Technical Reference Guide
5.8.4 AUDIO CODEC
The audio codec provides pulse code modulation (PCM) coding and decoding of audio
information as well as the selection and/or mixing of analog channels. As shown in Figure 5-13,
analog audio from a microphone, tape, or CD can be selected and, if to be recorded (saved) onto a
disk drive, routed through an analog-to-digital converter (ADC). The resulting left and right PCM
record data are muxed into a time-division-multiplexed (TDM) data stream (SD IN signal) that is
routed to the audio controller. Playback (PB) audio takes the reverse path from the audio
controller to the audio codec as SD OUT data and is decoded and either routed through an
equalizer or applied directly to the digital-to-analog converter (DAC). The codec supports
simultaneous record and playback of stereo (left and right) audio. The Sample Rate Generator
may be set for sampling frequencies up to 48 KHz.
The integrated analog mixer provides the computer control-console functionality handling
multiple audio inputs.
Audio
Format
HP Out R
HP Out L
SPDIF
EQ
EQ
ADC
PB
Data (R)
PB
Data (L)
DAC
DAC
Rec
Data (R)
ADC
Rec
Data (L)
S
E
L
(R)
(L)
(R)
(L)
PB
Gain
PB
Gain
Rec
Gain
Rec
Gain
Σ
/Mixer
CD In (R)
CD In (L)
Line In (R)
Line In (L)
Mic In
S
e
l
e
c
t
o
r
SD Out
SD IN
AC97
Link
I/F
Sample
Rate
Gen.
Right
Audio
Analog
Output
Circuits
Left
Audio
Audio
Controller
Figure 5-13. AD1981B Audio Codec Functional Block Diagram
All inputs and outputs are two-channel stereo except for the microphone input, which is inputted
as a single-channel but mixed internally onto both left and right channels. The microphone input
is the default active input. All block functions are controlled through index-addressed registers of
the codec.
5.8.5 AUDIO PROGRAMMING
hp compaq d330 and d530 Series of Personal Computers
Featuring the Intel Pentium 4 Processor
First Edition – June 2003
5-31

HP Compaq d330 DT Specifications

General

Brand	HP
Model	Compaq d330 DT
Category	Desktop
Language	English