Cirrus Logic CS4281-CQ, CS4281-CM Datasheet

CS4281

Product Data Sheet

FEATURES

Full DOS Games Compatibility via PC/PCI, DDMA, and CrystalClear Legacy Support

PCI V er si on 2. 1 Bu s Ma ste r

PC ’98 and PC ’99 C omp l i anc e

MPU-401 interface, FM Synthesizer, and Game Port

Full Duplex Operation

Hardware Volume Con tr o l

Win 95®, 98 (WDM), Win NT® 4.0, Win NT 5. 0

(WDM) Drivers

Advanced Power Management (PPMI)

Digital Docking Solution with AC ‘97 2.0 Codec

Support for Multi-Channel Audio Output

Hardware Sample Rate Conv ert er s

Pin-Comp a ti b le wit h C S46 1 4 an d CS4280-CM

CrystalClear™ PCI

Audio Interface

DESCRIPTION

The CS4281 is a PCI audio c ontroller with integrated legacy games support suitable for desktop and notebook PC designs. Wh en c om bi ned with dr iver s oftw ar e

and an AC ’97 codec such as the CS4297A, this device provides a complete high quality audio solution. Legacy compatibility is achieved via PC-PCI, DDMA, and CrystalClear Legacy Support. The product includes an integrated FM synthesizer and Plug-and-Play interface. In addition, the CS4281 offers hardware volume control and power management features. WDM drivers provide support for Windows 98

used with the CS4297 A, the CS428 1 is fully compliant

with Microsoft’s PC ’98 and PC ‘99 audio requirements. In the 100-pin MQFP package, the CS4281 is pin-compatible with the CS4614 and CS4280-CM.

ORDERING INFORMATION

CS4281-CM 100-pin MQFP 14x20x2.72mm CS4281-CQ 100-pin TQFP 14x14x1.4mm

and Windows NT®. When

Mixer SRC

DMA

Engine

Controller

Serial AC Link

PCI

PCI Bus

Interface

Interrupt

Control

I/O Register Array

MIDI &

Joystick

Support

PLL &

Clock

GPIO

Control

CIRRUS LOGIC PRODUCT DATA SHEET

DS308PP4 APR ‘99

CrystalClear™ PCI Audio Interface

TABLE OF CONTENTS

CHARACTERISTICS/SPECIFICATIONS- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 3

Absolute Maximum Ratings - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 3 Recommended Operating Conditions - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 3 AC Characteristics (PCI Signal P ins only) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 4 DC Characteristics - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 5 PCI Interface Pins- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 6 AC-Link Serial Interface- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 7 EEPROM Timing Characteristics - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 8

OVERVIEW- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 9

Legacy Support - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 9

SYSTEM ARCHITECTURES - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 9 HOST INTERFACE - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 11

PCI Bus Transactions - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 12 Configuration Space - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 12

Subsystem Vendor ID Fields- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 12 Cirrus-Specific Configuration Registers - - - - - - - - - - - - - - - - - - - - - - - - - - - 15

Interrupt Signal- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 20

AC ’97 LINK - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 20 MIDI PORT - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 22 JOYSTICK PORT - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 22 EEPROM INTERFACE - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 23 GENERAL PURPOSE I/O PINS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 23 PIN DESCRIPTION - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 24

PCI Interface - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 26 External Interface Pins - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 27 Clock / Miscellaneous - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 28 Serial Codec Interface- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 29

PACKAGE OUTLINE- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 30 APPENDIX A. MIGRATION FROM A CS4280 DESIGN TO A CS4281 DESIGN- - - - - 32

CS4281

Contacting Cirrus Logic Support

For a complete listing of Direct Sales, Distributor, and Sales Representative contacts, visit the Cirrus Logic web site at:

http://www.cirrus.com/corporate/contacts/

Preliminary product info rmation describes products which are in production, b ut for which full character izat i on da t a i s not yet available. Advance product information describes products which are in development and subject to development changes. Cirrus Logic, Inc. has made best efforts to ensure that the information contained in this document is accurate and reliable. However, the information is subject to change without notice and is provided “AS IS” without warranty of any

kind (express o r i mplie d). No re spon sibilit y is as sume d b y Cirru s Logic, Inc. for the use of this information, nor for infringements of patents or other rights of third parties. This document is the property of Cirrus Logic, Inc. and implies no license under patents, copyrights, trademarks, or trade secrets. No part of this publication may be copied, reproduced, stored in a retrieval system, or transmitted, in any form or by any means (electronic, mechanical, photographic, or otherwise) without the prior wri tten consent of Ci rrus Lo gic, Inc. Items fr om any Cir rus Logi c websit e or disk may be p rinte d for use by t he user . However , no part of the printout or electronic files may be copied, reproduced, stored in a retrieval system, or transmitted, in any form or by any means (electronic, mechanical, photographic, or otherwise) wi thout the prior wri tt en consent of Cirrus Log ic, Inc.Furthermore, no part of this publi cati on may be used as a basis for manufacture or sale of any items without the prior written consent of Cirrus Logic, Inc. The names of products of Cirrus Logic, Inc. or other vendors and suppliers appearing in this document may be trademarks or service marks of their respect ive owner s which may be registered in some jurisdi ctions. A li st of Ci rru s Logic, Inc. trademarks and service marks can be found at http://www.cirrus.com.

CrystalClear and CCLS are trademarks of Cirrus Logic, Inc. Windows, Windows 95, Windows 98, and Windows NT are registered trademarks of Microsoft Corporation. Intel is a registered trademark of Intel Corporation. Sound Blaster and Sound Blaster Pro are trademarks of Creative Technology, Ltd. All other names are trademarks, registered trademarks, or service marks of their respective companies.

CIRRUS LOGIC PRODUCT DATA SHEET

2 DS308PP4

CS4281

CrystalClear™ PCI Audio Interface

CHARACTERISTICS/SPECIFICATIONS

ABSOLUTE MAXIMUM RATINGS

(PCIGND = CGND = CRYGND = 0 V, all voltages with respect to 0 V)

Parameter Symbol Min Typ Max Unit

Power Supplies PCIVDD

VAUX CVDD

CRYVDD

VDD5REF Total Power Dissipation (Note 1) - - 1.0 W Input Current per Pin, DC (Except supply pins) - - ±10 mA Output current per pin, DC - - ±50 mA Digital Input voltage (Note 2) -0.3 - Vdd+

Ambient temperature (power applied) (Note 3) -55 - 125 °C Storage temperature -65 - 150 °C

4.6

5.5

0.3

V V V V V

Notes: 1. Includes all power generated by AC and/or DC output loading.

2. The power supply pins are at recommended maximum values.

3. At ambient temperatures above 70° C, total power dissipation must be limited to less than 0.4 Watts.

WARNING: Operation beyond these limits may result in permanent damage to the device.

Normal operation is not guaranteed at these extremes.

RECOMMENDED OPERATING CONDITIONS

(PCIGND = CGND = CRYGND = 0 V, all voltages with respect to 0 V)

Parameter Symbol Min Typ Max Unit

Power Supplies PCIVDD

VAUX

CVDD

CRYVDD

VDD5REF

Operating Ambient Temperature T

Specifications are subject to change without notice.

3.135 3 3

4.75 02570°C

3.3

3.3 5

3.6

3.465

3.6

5.25

V V V V V

CIRRUS LOGIC PRODUCT DATA SHEET

DS308PP4 3

CS4281

CrystalClear™ PCI Audio Interface

AC CHARACTERISTICS (PCI SIGNAL PINS ONLY)

(TA = 70° C; PCIVDD = CVDD = VAUX = CRYVDD = 3.3 V; VDD5REF = 5 V; PCIGND = CGND = CRYGND = 0 V;

Logic 0 = 0 V, Logic 1 = 3.3 V; Reference levels = 1.4 V; unless otherwise noted; (Note 4))

Parameter Symbol Min Max Unit

Switching Current High (Note 5)

0 < Vout ≤ 1.4

1.4 < Vout < 2.4

3.1 < Vout < 3.3

Switching Current Low (Note 5)

Vout ≥ 2.2

2.2 > Vout > 0.55

0.71 > Vout > 0

Low Clamp Current -5 < Vin ≤ -1 I

Output rise slew rate 0.4 V - 2.4 V load (Note 6) slew Output fall slew rate 2.4 V - 0.4 V load (Note 6) slew

-44

Vout 1.4–

44–

-------------------------+

0.024

Vout/0.023

Vin 1+

25–

------------------+

r f

15V/ns 15V/ns

0.015

(Note 7)

(Note 8)

-mA

mA mA

Notes: 4. Specifications guaranteed by characterization and not production testing.

5. Refer to V/I curves in Figure 1. Specification does not apply to PCICLK and RST# signals. Switching Current High specification does not apply to PME#, CLKRUN#, and INTA# which are open drain outputs.

6. Cumulative edge rate across specified range. Rise slew rates do not apply to open drain outputs.

7. Use Equation A in Figure below.

8. Use Equation B in Figure below.

Pull Down

Current (mA)

Vcc

2.4

Voltage

1.4

DC drive point

AC drive point

-2

Pull Up

-44 Current (mA)

test

point

-176

Vcc

2.2

Voltage

0.55

AC drive point

DC drive point

3, 6

Equation B:Equation A:

test

point

380

IOH = 11.9 × (Vout - 5.25) × (Vout + 2.45)

for 3.3 V > Vout > 3.1 V

IOL = 78.5 × Vout × (4.4 - Vout)

for 0 V < Vout < 0.71 V

Figure 1. AC Characteristics

CIRRUS LOGIC PRODUCT DATA SHEET

4 DS308PP4

CS4281

CrystalClear™ PCI Audio Interface

DC CHARACTERISTICS (T

= 70° C; PCIVDD = VAUX = CVDD = CRYVDD = 3.3 V; VDD5REF = 5 V;

PCIGND = CGND = CRYGND = 0 V; all voltages with respect to 0 V unless otherwise noted)

Parameter Symbol Min Typ Max Unit

PCI Interface Signal Pins

High level input voltage V Low level input voltage V High level output voltage Iout = -2 mA V Low level output voltage Iout = 3 mA, 6 mA (Note 9) V High level leakage current Vin = 2.7 V (Note 10) I Low level leakage current Vin = 0.5 V I PME# power off input leakage Vin = 5.25 V (Note 11) I

OFF

2-5.75V

-0.5 - 0.8 V

2.4 - - V

--0.55V

--70µA

---70µA

--1µA

Non-PCI Interface Signal Pins (Note 12) High level output voltage Iout = -5 mA (Note 13) V

Low level output voltage Iout = 5 mA V High level input voltage (Note 14) V Low level input voltage (Note 14) V High level leakage current Vin = 3.6 V (Note 14) I Low level leakage current Vin = 0 (Note 14) I

ol ih

0.9×Vdd - V

-0.1

0.65×Vdd Vdd+0.3 V

-0.3 0.35×Vdd V

-10µA

--10µA

Vdd V

Parameter Min Typ Max Unit

Power Supply Pins (Outputs Unloaded)

Power Supply Current: VDD5REF VAUX PCIVDD/CVDD/CRYVDD Total (Note 4)

0.6 TBD TBD

TBD

mA mA mA

Low Power Mode Supply Current - TBD - mA

Notes: 9. The following signals are tested to 6 mA: FRAME#, TRDY#, IRDY#, DEVSEL#, STOP#, PERR#, and

INTA#. All other PCI interface signals are tested to 3 mA.

10. Input leakage currents include hi-Z output leakage for all bi-directional buffers with three-state outputs.

11. Maximum allowable leakage into the PME# open-drain pin when power is removed from VAUX. Assumes no event occurred to drive PME# (idle state).

12. For AC-Link and VOLUP/DN pins, Vdd is VAUX. For all others Vdd is the core supply.

13. For open drain pins, high level output voltage is dependent on external pull-up used and number of attached gates.

14. All inputs that do not include internal pull-ups or pull-downs, must be externally driven for proper operation. If an input is not driven, it should be tied to power or ground, depending on the particular function. If an I/O pin is not driven and programmed as an input, it should be tied to power or ground through its own resistor.

CIRRUS LOGIC PRODUCT DATA SHEET

DS308PP4 5

CS4281

CrystalClear™ PCI Audio Interface

PCI INTERFACE PINS (T

= 0 to 70° C; PCIVDD = CVDD = VAUX = CRYVDD = 3.3 V; VDD5REF =

5 V; PCIGND = CGND = CRYGND = 0 V; Logic 0 = 0 V, Logic 1 = 3.3 V; Timing reference levels = 1.4 V)

Parameter Symbol Min Max Unit

PCICLK cycle time t PCICLK high time t PCICLK low time t PCICLK to signal valid delay - bused signals t PCICLK to signal valid delay - point to point t

val(p+p)

Float to active delay (Note 15) t Active to Float delay (Note 15) t Input Set up Time to PCICLK - bused signals t Input Set up Time to PCICLK - point to point t

su(p+p)

Input hold time for PCICLK t Reset active to output float delay (Notes 15, 16, 17) t

cyc

high

low

val

on off su

rst-off

30 - ns

11 - ns 11 - ns

211ns 212ns 2-ns

-28ns

7-ns

10, 12 - ns

0-ns

-30ns

Notes: 15. For Active/Float measurements, the Hi-Z or “off” state is when the total current delivered is less than or

equal to the leakage current. Specification is guaranteed by design, not production tested.

16. RST# is asserted and de-asserted asynchronously with respect to PCICLK.

17. All PCI output drivers are asynchronously floated when RST# is active. Note ASDOUT and ASYNC are not affected by RST#.

PCICLK

RST#

OUTPUTS

Hi-Z

OUTPUTS

Valid

INPUTS

off

val

Valid Input

rst-off

Figure 2. PCI Timing Measurement Conditions

CIRRUS LOGIC PRODUCT DATA SHEET

6 DS308PP4

CS4281

CrystalClear™ PCI Audio Interface

AC-LINK SERIAL INTERFACE (T

= 0 to 70° C; PCIVDD = CVDD = VAUX = CRYVDD = 3.3 V;

VDD5REF = 5 V; PCIGND = CGND = CRYGND = 0 V; Logic 0 = V

Parameter Symbol Min Typ Max Unit

ABITCLK input cycle time t

clk_period

ABITCLK input high time t ABITCLK input low time t ABITCLK input rise/fall time t ASDIN/ASDIN2 valid to ABITCLK falling t ASDIN/ASDIN2 hold after ABITCLK falling t ASDIN/ASDIN2 input rise/fall time t ABITCLK rising to ASDOUT/ASYNC valid, C ASYNC/ASDOUT rise/fall time, C

clk_period

= 55 pF t

clk_high

clk_low

, Logic 1 = Voh,Vih; unless otherwise noted)

ol,Vil

81.4 - ns

clk_high

clk_low

rfclk

setup

hold

rfin

rfout

36 40.7 45 ns 36 40.7 45 ns

2-6ns 10 - - ns 10 - - ns

2-6ns

2 - 15 ns

2-6ns

ABITCLK

ASDIN/ASDIN2

ASDOUT

ASYNC

rfclk

setup

hold

rfclk

rfout

Figure 3. AC ’97 Configuration Timing Diagram

rfin

rfout

CIRRUS LOGIC PRODUCT DATA SHEET

DS308PP4 7

CS4281

CrystalClear™ PCI Audio Interface

EEPROM TIMING CHARACTERISTICS Note 4. (T

= 0 to 70 °C, PCIVDD = CVDD = VAUX =

CRYVDD = 3.3 V; VDD5REF = 5 V; VDD5REF = 5 V; PCIGND = CGND = CRYGND = 0 V; Logic 0 = 0 V, Logic 1 = 3.3 V; Timing reference levels = 1.4 V; PCI clock frequency = 33 MHz; unless otherwise noted)

Parameter S ymbol Min Ma x Units

EECLK Low to EEDAT Data Out Valid t Start Condition Hold Time t EECLK Low t EECLK High t Start Condition Setup Time (for a Repeated Start Condition) t EEDAT In Hold Time t EEDAT In Setup Time t

HD:STA

LEECLK

HEECLK

SU:STA HD:DAT SU:DAT

EEDAT/EECLK Rise Time (Note 18) t EEDAT/EECLK Fall Time t Stop Condition Setup Time t

SU:STO

EEDAT Out Hold Time t

R F

07.0µs

5.0 10 10 -

5.0 -

µ µ µ µ

0-µs

250 - ns

-1µs

- 300 ns

5.0 -

0-µs

s s s s

Notes: 18. Rise time on EEDAT is determined by the capacitance on the EEDAT line with all connected gates and

the required external pull-up resistor.

EECLK

EEDAT (IN)

EEDAT (OUT)

SU:STA

LEECLK

HD:STA

HEECLK

HD:DAT

Figure 4. EEPROM Timing

SU:DAT

SU:STO

CIRRUS LOGIC PRODUCT DATA SHEET

8 DS308PP4

CS4281

CrystalClear™ PCI Audio Interface

OVERVIEW

The CS4281 provides a low-cost PCI audio solution with Legacy Game com patibilit y for the P C environment. The CS4281 is compatible with the CS4614 and CS4280-CM. The CS4281 is divided into several functional blocks.

• PCI Interface

• Sound System Interface

• FM Synthesis

• Peripheral Devices (MIDI & Gameport)

The PCI Interface is the physical connection to the bus. It is subdivided into several smaller functional groups such as: PCI configuration and interface, DMA controller, interrupt control, and chip control. The PCI interface serves as a Master/Target PCI device and its two-base address registers provide access to the chip operation registers and internal memory blocks. The Sound System Interface provides all the registers and controls to operate the entire sou nd system. The FM Synthes is provides full compa tibility with market standard FM-based music synthesis used in DOS games and educational software. The CS4281’s flexibility is further enhanced by the inclusion of peripheral devices such as Hardware Volume Control, Clock Generation, General Purpose I/O (GPIO), MIDI UART Port, Game (Joystick) Port, and the AC Link.

The DMA Engine provides dedicated hardware to manage transfer of up to 4 concurrent audio/data streams to and from host memory buffers. Four Bus Mastering DMA controllers support simultaneous capture, play, modem transmit, and modem receive.

The CS4281 supports a variety of audio I/O configurations including a single CS4297A CrystalClear AC ’97 Codec or dual CS4297A codecs where the second codec is used as a portable’s docking station solution. The combination of a CS4281 with a CS4298 AMC ‘97 codec, provides a cost-effective, superior quality, two-chip audio/modem solution.

Legacy Support

Legacy games are supported by CrystalClear Legacy Support CCLS™, DDMA, or by the PC/PCI interface. In both motherboard and add-in card designs, CCLS and DDMA provide support for legacy games by providing a hardware interface that supports a Sound Blaster Pro™ compatible interface, as well as support for FM, and joystick interfaces. These ha rdware in terface s provide PC I-only gam es compa tibi lity for real-mode DOS and Windows DOS box support.

For motherboard designs, PC/PCI is used by connecting the PCGNT# and PCREQ# pins to the appropriate pins on the south bridge motherboard chip. The PC/PCI interface is compliant with Intel’s PC/PCI spec. (version 1.2).

SYSTEM ARCHITECTURES

A typical system diagram depicting connection of the CS4281 to the CrystalClear CS4297A AC ’97 Codec is given in Figure 5. All analog audio inputs and outputs are connected to the CS4297A. Audio data is passed between the CS4297A and the CS4281 over the serial AC-Link. The CS4281 provides a hardware interface for connection of a joystick and MIDI devices.

Figure 6 depicts the CS4281 using both AC ‘97 codec interfaces in a portable design. The primary AC ‘97 interface is connected to a CS4297A used for all audio I/O inside and connected to the portable. The second AC ‘97 interface is sent across to the docking station which contains a second CS4297A. The second codec

CIRRUS LOGIC PRODUCT DATA SHEET

DS308PP4 9

CS4281

CrystalClear™ PCI Audio Interface

CPU

North

Bridge

Host

Memory

PCI Bus

South

Bridge

CS4281

CS4297A

Audio Out

Audio In

PC/PCI (if used)

Figure 5. AC ‘97 Codec Interface

is activated when the portable is in the docking station. Software can disable the audio I/O paths on the portable that are superseded by docking station I/O and enable the paths needed in the docking station. Note that both interfaces are needed in systems where the CD-ROM analog input is in the portable and the

Line In/Out jacks on the docking stations are used. Using the AC ‘97 digital link across the dock maintains the absolute highest audio quality along with a standard well-defined non-proprietary interface that will last through many system generations.

Figure 7 depicts the CS4281 using an AC ‘97 codec in an audio/modem design. The primary AC ‘97 interface is connected to a CS4298 and is used for audio/modem I/O such as Mic In, Line In, Line Out and the Analog Front End (AFE) for Modem features. The CS4298 analog interface is connected to the DAA via the EGPIO pins. The EGPIO supports the PCI Power Management Event system wake-up feature allowing a powerdown system to be powered up by an incoming call on the modem.

PORTABLE

CPU

South

Bridge

North

Bridge

PCI Bus

CS4281

PCI Audio Interface

Secondary

Serial Data

(ASDIN2)

PC/PCI

(if used)

Primary AC-Link

Host

Memory

Bridge

CS4297A

Buffer

Audio

Out

Audio

DOCKING STAT ION

Secondary PCI Bus

CS4297A

Audio Out

Audio In

Figure 6. Portable Docking Station Scenario

CIRRUS LOGIC PRODUCT DATA SHEET

10 DS308PP4

CS4281

CrystalClear™ PCI Audio Interface

CPU

South

Bridge

North

Bridge

PCI Bus

CS4281

PCI Audio Interface

AC-Link

PC/PCI

(if used)

Host

Memory

CS4298

DAA

Audio Out

Audio In

Telephone

Line

Figure 7. Modem Scenario

HOST INTERFACE

The CS4281 host interface is comprised of two separate interface blocks which are memory mapped into host address space. The interface blocks can be located anywhere in the host 32-bit physical address space. The interface block locations are defined by the addresses programmed into the two Base Address Regis-

ters in the PCI Configuration Space. These base addresses are normally set up by the system’s Plug and Play BIOS. The first interface block (Base Address 0) contains the general purpose configuration, control, and status registers for the device. The second interface block (Base Address 1) maps the FIFO RAMs into host memory space. The relationship between the Base Address Registers in the CS4281 PCI Configuration Space and the host memory map is depicted in Figure 8. The bus mastering PCI bus interface complies with the PCI Local Bus Specification (version 2.1).

Device PCI Config. Space

00h

Device ID / Vendor ID 04h 08h

0Ch

10h 14h

Status / Command

Class Code / Revision

Misc. Control Base Address Register 0 Base Address Register 1

Direct Registers

(Memory Mapped, 4 kByte)

Direct Memory Interface

(Memory Mapped, 6 kByte)4

Figure 8. Host Interface Base Address Registers

CIRRUS LOGIC PRODUCT DATA SHEET

DS308PP4 11

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