IEI Technology IMB-9454G-R20, User Manual

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IMB-9454G Motherboard
are also mounted on the northbridge and southbridge chipsets to ensure the operating
temperature of these chips remain low.
2.16 Audio Codec
The IMB-9454G has an integrated REALTEK ALC655 CODEC. The ALC655 CODEC is a
16-bit, full-duplex AC'97 Rev. 2.3 compatible six-channel audio CODEC designed for PC
multimedia systems, including host/soft audio and AMR/CNR-based designs. Some of the
features of the codec 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 analog line-level stereo inputs with 5-bit volume control, LINE_IN, CD,
AUX
High-quality differential CD input
Two analog 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
LINE input shared with surround output; MIC input shared with Center and
LFE output
Built-in 50mW/20ohm amplifier for both Front-out and Surround-Out
External Amplifier Power Down (EAPD) capability
Power management and enhanced power saving features
Supports Power-Off CD function
Adjustable VREFOUT control
Supports 48KHz S/PDIF output, complying with AC'97 Rev 2.3 specifications
Supports 32K/44.1K/48KHz S/PDIF input
Power support: Digital: 3.3V; Analog: 3.3V/5V
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