Intel Pentium 4 User Manual

Introduction
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Intel
®
Pentium
®
4 Processor / Intel
®
850 Chipset Family Platform Design Guide 25
1.4.2.2 Intel
®
AC’97 6-Channel Support
The Audio Codec ’97 (AC’97) Specification defines a digital link that can be used to attach an
audio codec (AC), a modem codec (MC), an audio/modem codec (AMC), or both an AC and an
MC. The AC’97 Specification defines the interface between the system logic and the audio or
modem codec known as the AC-link.
The ICH2 AC’97 (with the appropriate codecs) not only replaces ISA audio and modem
functionality, but also improves overall platform integration by incorporating the AC-link. Using
the ICH2 integrated AC-link reduces cost and eases migration from ISA.
By using an audio codec, the AC-link allows for cost-effective, high-quality, integrated audio on
the Intel 850 chipset platform. In addition, an AC’97 soft modem can be implemented with the use
of a modem codec. Several system options exist when implementing AC’97. The ICH2 integrated
digital link allows two external codecs to be connected to the ICH2 in several configurations.
Refer to Table 2 for the various Intel AC’97 codec implementations.
Table 2. Intel
®
ICH2 Codec Options
Primary Secondary
Audio (AC) None
Modem (MC) None
Audio/Modem (AMC) None
Audio (AC) Modem (MC)
Audio (AC) Audio (AC)
Audio (AC) Audio/Modem (AMC)
Modem implementation for different countries must be considered as telephone systems vary. By
using a split design, the audio codec can be on-board and the modem codec can be placed on a
riser. Intel is developing an AC-link connector. With a single integrated codec, or AMC, both
audio and modem can be routed to a connector near the rear panel where the external ports can be
located.
The digital link in the ICH2 is AC’97 Revision 2.1 compliant, supporting two codecs with
independent PCI functions for audio and modem. Microphone input and left and right audio
channels are supported for a high quality two-speaker audio solution. Wake on ring from suspend
is also supported with an appropriate modem codec. The Intel 850 chipset-based platform expands
audio capability with support for up to six channels of PCM audio output (full AC3 decode). Six
channel audio consists of Front Left, Front Right, Back Left, Back Right, Center and Woofer for a
complete surround sound effect.
Refer to the AC’97 Specification, Revision 2.1 at http://developer.intel.com/pc-
supp/platform/ac97/ for complete details.

Intel Pentium 4 Specifications

General

Brand	Intel
Model	Pentium 4
Category	Computer Hardware
Language	English