Eurotech ALUDRA, User Manual

Page: 20 / 123

ALUDRA user manual
Issue A
20
Intel
®
ICH7-M Audio Codec ’97 Controller
The Audio Codec ’97 (AC’97) controller integrated into the ICH7-M complies with AC’97
Component Specification, Version 2.3. The AC’97 controller is integrated to a RealTek
ALC655 audio codec. The RealTek ALC655 is in turn connected to on-board audio
connectors, which are then connected to compliant audio devices. The RealTek ALC655
is a 16-bit, full-duplex AC'97 Rev. 2.3 compatible six-channel audio codec. The codec
and the audio connectors are shown in
Figure 11 .
Figure 11: Audio Codec and Connectors
Some of the features of the RealTek ALC655 are listed below:

Meets performance requirements for audio on PC99/2001 systems

Meets Microsoft WHQL/WLP 2.0 audio requirements

16-bit Stereo full-duplex CODEC with 48KHz sampling rate

Compliant with AC'97 Rev 2.3 specifications
- Front-Out, Surround-Out, MIC-In and LINE-In Jack Sensing
- 14.318MHz -> 24.576MHz PLL to eliminate crystal
- 12.288MHz BITCLK input
- Integrated PCBEEP generator to save buzzer
- Interrupt capability

Three analogue line-level stereo inputs with 5-bit volume control, LINE_IN, CD, AUX

High-quality differential CD input

Two analogue line-level mono inputs: PCBEEP, PHONE-IN

Two software selectable MIC inputs

Dedicated Front-MIC input for front panel applications (software selectable)

Boost preamplifier for MIC input