ad1812 Analog Devices, Inc., ad1812 Datasheet - Page 12

• Manufacturer Part Number: ad1812
• Description: Soundport Controller
• Manufacturer: Analog Devices, Inc.

Power Supplies
Pin Name
V
GNDA
V
GNDD
ADVDD
ADGND
V
GNDG
AD1812
(continued from Page 1)
HOST PC INTERFACE
All necessary ISA bus interface logic is completely contained on-
chip. This includes address decoding for all onboard resources,
control and signal interpretation, DMA selection and control
logic, IRQ selection and control logic, and all interface configu-
ration logic (see Table IV).
The AD1812 supports a DMA request/grant architecture for
transferring data with the ISA bus. One, two, or three DMA
channels can be supported. Programmed I/O (PIO) mode is
also supported for control register accesses and for applications
lacking DMA control. The AD1812 includes dual DMA count
registers for full-duplex operation enabling simultaneous capture
and playback on separate DMA channels.
The AD1812 is fully configurable according to the Plug and
Play ISA specification. In a non-Plug and Play environment, the
built in Plug and Play protocol can be disabled. When Plug and
Play is disabled, the AD1812 operates under a fixed address
space.
Logical
Device
Number
0
1
2
3
4
5*
*If MODEM_EN is asserted.
CC
DD
DDG
Table IV. Emulated Logical Devices
Emulated
Windows Sound System
Sound Blaster Pro v. 2.01
OPL3 Music Synthesizer
MIDI MPU-401 Port
Game/Joystick Port
Modem
Device
P/TQFP
51, 61, 72
52, 62, 74
6, 17, 28, 91,
94, 104, 107,
116, 126, 132,
135, 140, 146,
149, 154
5, 16, 27, 34, 82,
83, 86, 92, 93,
105, 106, 117,
127, 133, 134,
141, 147, 148,
155
80
79
50
45
I/O
I
I
I
I
I
I
I
I
PnP
Compatible
Device
—
PNPB002
PNPB020
PNPB006
PNPB02F
PNP0501
Description
Analog Supply Voltage (+5 V).
Analog Ground.
Digital Supply Voltage (+5 V).
Digital Ground.
Analog/Digital Supply Voltage. Connect to +5 V
Analog/Digital Ground. Connect to analog ground plane.
Game Port Digital Voltage Supply. Connect to +5 V
Game Port Digital Ground. Connect to the digital ground plane.
–12–
WSS COMPATIBLE CODEC
The AD1812 contains the AD1845 SoundPort Stereo Codec for
business audio support and multimedia applications. The codec
includes stereo audio converters, complete on-chip filtering,
MPC Level-2 compliant analog mixing, programmable gain and
attenuation, a variable sample frequency generator, and FIFOs
buffering the ISA bus.
The codec includes a stereo pair of
verters and a stereo pair of
puts to the ADC can be selected from four stereo pairs of analog
signals: line (LINE), microphone (MIC), auxiliary line #1
(AUX1), and post-mixed DAC output. In addition, an analog
mixer allows a mono input (MONO_IN), MIC, AUX1, LINE
and auxiliary line #2 (AUX2) to be mixed with the DACs’ out-
put. A software-controlled programmable gain stage allows in-
dependent gain for each channel going into the ADC. The
ADCs’ output can be digitally mixed with the DACs’ input.
The pair of 16-bit outputs from the ADCs are available over a
16-bit bidirectional interface that also supports 16-bit digital in-
put to the DACs and control information. The codec can accept
and generate 16-bit twos-complement PCM linear (big endian
or little endian) digital data, 4-bit IMA-ADPCM compatible
digital data, 8-bit unsigned magnitude PCM linear data, and
8-bit -law or A-law companded digital data.
The AD1812 includes a variable sample frequency generator,
which allows the codec to instantaneously change sample rates
from 5.5 kHz to 50 kHz with a resolution of 1 Hz. This is a su-
perb way to create special audio effects.
digital-to-analog converters. In-
analog-to-digital con-
CC
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DD
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