Functional Description
5-132
Intel
82801BA ICH2 Datasheet
5.18
AC’97 Controller Functional Description
(Audio D31:F5, Modem D31:F6)
Note:
All references to AC’97 in this document refer to the AC’97 2.1 specification. For further
information on the operation of the AC-link protocol, see the AC’97 specification.
The ICH2 AC ‘97 Controller features include:
Independent PCI functions for audio and modem.
Independent bus master logic for Mic input, PCM Audio input (2-channel stereo), PCM audio
output (2, 4 or 6-channel stereo), Modem input and Modem output.
16 bit sample resolution
Multiple sample rates up to 48 KHz
16 GPIOs
Single modem line
Dual codec configuration with two SDIN pins
Table 5-89
shows a detailed list of features supported by the ICH2 AC’97 digital controller.
.
Table 5-89. Featured Supported by ICH2
Feature
Description
System Interface
Isochronous low latency bus master memory interface
Scatter/gather support for word-aligned buffers in memory
(all mono or stereo 16-bit data types are supported, no 8-bit data types are supported)
Data buffer size in system memory from 3 to 65535 samples per input
Data buffer size in system memory from 0 to 65535 samples per output
Independent PCI audio and modem functions with configuration and IO spaces
AC’97 codec registers are shadowed in system memory via driver (not PCI IO space)
AC’97 codec register accesses are serialized via semaphore bit in PCI IO space (new
accesses are not allowed while a prior access is still in progress)
Power
Management
Power management via ACPI control methods
Support for audio states:
D0, D2, D3hot, D3cold
Support for modem states:
D0, D3hot, D3cold
SCI event generation for PCI modem function with wake-up from
D3cold
Independent codec D3 w/ Link down event, synchronized via two bit semaphore (in
PCI IO Space)
PCI Audio
Function
Read/write access to audio codec registers 00h-3Ah and vendor registers 5Ah–7Eh
16-bit stereo PCM output, up to 48 kHz (L,R, Center, Sub-woofer, L-rear and R-rear
channels on slots 3,4,6,7,8.9)
16-bit stereo PCM input, up to 48 kHz (L,R channels on slots 3,4)
16-bit mono mic in w/ or w/o mono mix, up to 48 kHz (L,R channel, slots 3,4) (mono
mix supports mono hardware AEC reference for speakerphone)
16-bit mono PCM input, up to 48 kHz from dedicated mic ADC (slot 6)
(supports speech recognition or stereo hardware AEC ref for speakerphone)
During cold reset AC_RST# is held low until after POST and software deassertion of
AC_RST# (supports passive PC_BEEP to speaker connection during POST)
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