82801BA Datasheet, PDF (204/498 Pages) Intel Corporation – Intel 82801BA I/O Controller Hub 2 (ICH2) and Intel 82801BAM I/O Controller Hub 2 Mobile

Functional Description
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 5-88 shows a detailed list of features supported by the ICH2 AC’97 digital controller.
.
Table 5-88. Featured Supported by ICH2
Feature
System Interface
Power
Management
PCI Audio
Function
Description
• 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 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)
• 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)
5-142
82801BA ICH2 and 82801BAM ICH2-M Datasheet