CS4281 Datasheet, PDF (20/36 Pages) Cirrus Logic – CrystalClear PCI Audio interface

CS4281
CrystalClear™ PCI Audio Interface
Interrupt Signal
The CS4281 PCI Interface includes an interrupt controller function which receives interrupt requests from
multiple sources within the CS4281 device, and presents a single interrupt line (INTA) to the host system.
Interrupt control registers in the CS4281 provide the host interrupt service routine with the ability to iden-
tify the source of the interrupt and to clear the interrupt sources.
ISA interrupts are provided for real-mode DOS support. The three ISA interrupt pins are high-impedance
when the CS4281 powers up. The output enables for a particular ISA interrupt are a combination of bits
set by the BIOS and an interrupt enable bit controlled by start-up configuration software.
AC ’97 LINK
The CrystalClear solution includes a CS4281 plus a CS4297A. The CS4281 communicates with the
CS4297A over the AC-Link as specified in the Intel^® Audio Codec ‘97 Specification (version 2.1). A
block diagram for the AC ’97 Controller configuration is given in Figure 5. The signal connections be-
tween the CS4281 and the AC ’97 Codec are indicated in Figure 9.
CS4281
ABITCLK
ASYNC
ASDOUT
ASDIN
ARST#
MIDIIN
MIDIOUT
JACX, JACY, JBCX, JBCY
JAB1, JAB2, JBB1, JBB2
12.288 MHz
48 kHz
24.576 MHz
BIT_CLK
SYNC
SDATA_OUT
SDATA_IN
RESET#
CS429 7A
Joystick/
MIDI Port
Figure 9. Single AC ‘97 Codec Connection Diagram
CIRRUS LOGIC PRODUCT DATA SHEET
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DS308PP4