82801CA Datasheet, PDF (214/521 Pages) Intel Corporation – I/O Controller Hub 3-S (ICH3-S)

Functional Description
5.18.1 AC-Link
The ICH3 is an Audio Codec ’97, Revision 2.2 controller that communicates with companion
codecs via a digital serial link called the AC-link. All digital audio/modem streams and command/
status information is communicated over the AC-link.
The AC-link is a bi-directional, serial PCM digital stream. It handles multiple input and output data
streams, as well as control register accesses, employing a time division multiplexed (TDM)
scheme. The AC-link architecture provides for data transfer through individual frames transmitted
in a serial fashion. Each frame is divided into 12 outgoing and 12 incoming data streams, or slots.
The architecture of the ICH3 AC-link allows a maximum of two codecs to be connected.
Figure 5-20 shows a two codec topology of the AC-link for the ICH3.
Figure 5-20. Audio Codec ’97, Revision 2.2 Controller-Codec Connection
D ig ita l
AC'97 2.2 Controller
AC'97 2.2
Controller
Section
of the
ICH
RESET#
SDOUT
SYNC
BIT_CLK
SDIN 0
SDIN 1
AC'97 / AC'97 2.2 /
AMC'97 2.2
P rim a ry
Codec
AC'97 / MC '97 2.2 /
AMC'97 2.2
Secondary
Codec
The AC-link consists of a five signal interface between the controller and codec. Table 5-98
indicates the AC-link signal pins on the ICH3 and their associated power wells.
Table 5-98. AC ’97 Signals
Signal Name
AC_RESET#
AC_SYNC
AC_BIT_CLK
AC_SDOUT
AC_SDIN 0
AC_SDIN 1
Type
Output
Output
Input
Output
Input
Input
Power Well¹
Resume
Core
Core
Core
Resume
Resume
Description
Master hardware reset
48 kHz fixed rate sample
sync
12.288 MHz Serial data clock
Serial output data
Serial input data
Serial input data
NOTES:
1. Power well voltage levels are 3.3 V
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Intel^® 82801CA ICH3-S Datasheet