82C931 Datasheet, PDF (27/64 Pages) List of Unclassifed Manufacturers – Plug and Play Integrated Audio Controller

82C931
4.0 Functional Description
The 82C931 is an optimized single chip solution with built-in
Plug-and-Play functions, built-in FM synthesizer and 16-bit
Sigma-Delta Codec to provide all of the features needed to
create the following sound characteristics and applications:
• 16-bit sound quality Sound Blaster Pro and Windows
Sound System compatible card
• 22 voice FM synthesis
• 16-bit CD-quality digital wave audio up to 44.1KHz stereo
• Game port
• MPU-401 MIDI interface
• Wavetable synthesis upgrade
The following sub-sections will discuss these built-in func-
tions in detail.
4.1 Plug and Play
The OPTi 82C931 supports the ISA Plug and Play (PnP)
Specification 1.0a. After power-up, the 82C931 is isolated
from other PnP cards in the host system by the system soft-
ware. With this mechanism, the I/O address, IRQ and DMA
usage of the 82C931 can be configured by the system
according to the free resources available. As a result, the
chance of getting a resource conflict is minimized.
The PnP function is disabled by pulling pin 12 (PNPEN) of
the 82C931 low at power-up; otherwise the 82C931 will oper-
ate in PnP mode.
A PnP configuration sequence is carried out by either the
system BIOS supporting PnP or Configuration Manager soft-
ware of the operating system. It is used to map the various
functional blocks (logical devices) within the 82C931 into the
host system address space as well as to configure the DMA
and IRQ channels. The configuration sequence occurs as fol-
lows:
1. The 82C931 is isolated from the system.
2. A unique indentifier (handle) is programmed into the
82C931 and the resource data is read.
3. After the resource requirement and capabilities are
determined, the handle is used to assign conflict-free
resources by programming the appropriate information
into the 82C931 configuration registers a logical device
at a time
4. After the configuration registers are programmed, the
82C931 leaves the configuration mode and each logical
device is activated individually. The bus interface of each
logical device is then enabled.
The 82C931 supports the following logical devices:
• IDE CD-ROM interface
• Windows Sound System
• FM synthesis
• Sound Blaster Pro
• Game Port
• MPU-401 MIDI interface
• Modem interface
• 82C931 Master Control
912-3000-035
Revision: 2.1
OPTi
®
Page 19