Cirrus Logic CDB4245 User Manual

Evaluation Board for CS4245

CDB4245

Features

z Single-ended Analog Inputs
z Single-ended Analog Outputs
z CS8406 S/PDIF Digital Audio Transmitter
z CS8416 S/PDIF Digital Audio Receiver
z Independent ADC and DAC Clock Domains
z Header for Optional External Software

Configuration of CS4245

z Header for External PCM Serial Audio I/O
z 3.3 V Logic Interface
z Pre-defined Software Scripts
z Demonstrates Recommended Layout and

Grounding Arrangements

z Windows

to Configure CS4245 and Inter-board
Connections

ORDERING INFORMATION

CDB4245 Evaluation Board

®

Compatible Software Interface

Description

The CDB4245 evaluation board is an excellent means
for evaluating the CS4245 CODEC. Evaluation requires
an analog/digital signal source and analyzer, and power
supplies. A Windows
used to evaluate the CS4245.

System timing for the I²S, Left-Justified and Right-Justi­fied interface formats can be provided by the CS4245,
the CS8416, the CS8406, or by a PCM I/O stake header
with an external source connected.

RCA phono jacks are provided for the CS4245 analog in­puts and outputs. Digital data I/O is available via RCA
phono or optical connectors to the CS8416 and CS8406.

The Windows

®

uration of the CDB4245 easy. The software
communicates through the PC’s serial port to configure
the control port registers so that all features of the
CS4245 can be evaluated. The evaluation board may
also be configured to accept external timing and data
signals for operation in a user application during system
development.

®

PC compatible computer must be

software provides a GUI to make config-

I

Cirrus Logic, Inc.

www.cirrus.com

Passive Input Filter

M

Active Input Filter

Microphone Input

Master Clock Master Clock

Canned

Oscillator

Header

CS8416 CS8406

U

X

CS4245

Control Port Interface

CS8416 CS8406

FPGA

Sub-clocks and Data

Copyright © Cirrus Logic, Inc. 2005

(All Rights Reserved)

Passive Output Filter

Active Output Filter

Test Points

Canned

Oscillator

Header

FEB ‘05

DS656DB1

TABLE OF CONTENTS

1. SYSTEM OVERVIEW ............................................................................................................... 4

1.1 Power ..... ....................................... ... ... ... ....................................... ... .... ... ... ........................4

1.2 Grounding and Power Supply Decoupling ......................................................................... 4

1.3 CS4245 Audio CODEC ...................................................................................................... 4

1.4 CS8406 Digital Audio Transmitter ......................................................................................4

1.5 CS8416 Digital Audio Receiver .......................................................................................... 4

1.6 FPGA .................................................................. .... ... ... ... .... ... ... ........................................ 5

1.7 Canned Oscillators .............................................................................................................5

1.8 External Control Headers ...................................................................................................5

1.9 Analog Inputs ............ .... ... ... ....................................... ... ... .... ..............................................5

1.10 Analog Outputs ................................................................................................................5

1.10.1 DAC Outputs ....................................................................................................... 5

1.10.2 Auxiliary Outputs .................................................................................................5

1.11 Serial Control Port ............................................................................................................ 5

1.12 USB Control Port ............................................................................................................. 6

2. SYSTEM CLOCKING ............................................................................................................... 6

2.1 Clock Domain 1 ................................... ... ....................................... ... .... ... ........................... 6

2.2 Clock Domain 2 ................................... ... ....................................... ... .... ... ........................... 6

3. SYSTEM DATA ROUTING .......................................................................................................6

3.1 CS4245 SDIN Source ........................................................................................................6

3.2 CS8406 SDIN Source ........................................................................................................6

4. PC SOFTWARE CONTROL .....................................................................................................7

4.1 CDB4245 Controls Tab ....... ... .... ... ... ... .......................................... ..................................... 7

4.2 S/PDIF I/O Controls Tab ....................................................................................................8

4.3 Register Maps Tab ..................................... ... ... ... .... ... ... ....................................... ... ... ... ..... 9

4.4 Pre-Configured Script Files . ... .... ... ... ... ... .... ... ... ....................................... ... ... .... ... ... ... ... .....9

4.4.1 Oscillator Clock - ADC Ch 1 to DAC & SPDIF Out ............................................... 9

4.4.2 SPDIF Recovered Clock - SPDIF to DAC & ADC to SPDIF ...............................10

5. FPGA REGISTER QUICK REFERENCE ...............................................................................11

6. FPGA REGISTER DESCRIPTION .........................................................................................12

7. CDB CONNECTORS, JUMPERS, AND SWITCHES .............................................................15

8. CDB BLOCK DIAGRAM ..................................................................................................... 17

9. CDB SCHEMATICS ............................................................................................................... 18

10. CDB LAYOUT ...................................................................................................................... 26

11. REVISION HISTORY ............................................................................................................ 29

CDB4245

2 DS656DB1

LIST OF FIGURES

Figure 1. CDB4245 Controls Tab.................................................................................................... 7

Figure 2. S/PDIF I/O Controls Tab.................................................................................................. 8

Figure 3. Register Maps Tab........................................................................................................... 9

Figure 4. Block Diagram................................................................................................................ 17

Figure 5. CS4245.......................................................................................................................... 18

Figure 6. Analog Inputs................................................................................................................. 19

Figure 7. Analog Outputs.............................................................................................................. 20

Figure 8. S/PDIF I/O...................................................................................................................... 21

Figure 9. Control Port.................................................................................................................... 22

Figure 10. FPGA........................................................................................................................... 23

Figure 11. Discrete Clock Routing and Level Shifting................................................................... 24

Figure 12. Power........................................................................................................................... 25

Figure 13. Silk Screen................................................................................................................... 26

Figure 14. Topside Layer.............................................................................................................. 27

Figure 15. Bottom side Layer........................................................................................................ 28

LIST OF TABLES

Table 1. MCLK2 Source ... ... ....................................... ... ... .... ... ... ... ....................................... ......... 12

Table 2. MCLK1 Source ... ... ....................................... ... ... .... ... ... ... ....................................... ......... 12

Table 3. DAC Subclock Source..................................................................................................... 13

Table 4. ADC Subclock Source..................................................................................................... 13

Table 5. SDIN1 Source................................................................................................................. 14

Table 6. CS8406 SDIN Source.....................................................................................................14

Table 7. System Connections....................... ... ... .... ...................................... .... ... ... ... .... ... ............ 15

Table 8. System Jumper Settings........................... ... ... ... .... ... ... ... .... ... ... ......................................16

Table 9. Revision History.............................................................................................................. 29

CDB4245

DS656DB1 3

CDB4245

1. SYSTEM OVERVIEW

The CDB4245 evaluation board is an excellent means for evaluating the CS4245 CODEC. Analog and dig ital audio
signal interfaces are provided, an on-board FPGA is used for easily configuring the evaluatio n platform, a nd a 9-pi n
serial cable is included for use with the supplied Windows

The CDB4245 schematic set is shown in Figures 5 through 12.

1.1 Power

Power must be supplied to the evaluation board through the red +5.0V binding post. On-board regulators
provide 3.3 V, 2.5 V, and 1.8 V supplies. Appropriate supply levels for powering VA, VD, VLS, and VLC are
set by a series of jumpers (see Table 8 on page 16). All voltage inputs must be referenced to the single black
binding post ground connector (see Table 7 on page 15).

WARNING: Please refer to the CS4245 data sheet for allowable voltage levels.

1.2 Grounding and Power Supply Decoupling

The CS4245 requires careful attention to power supply and grounding arrangements to optimize perfor­mance. Figure 4 on page 17 provides an overview of the connections to the CS4245. Figure 13 on page 26
shows the component placement. Figure 14 on page 27 shows the top layout. Figure 15 on page 28 shows
the bottom layout. The decoupling capacitors are located as close to the CS4245 as possible. Extensive use
of ground plane fill in the evaluation board yields large reductions in radiated noise.

1.3 CS4245 Audio CODEC

A complete description of the CS4245 is included in the CS4245 product data sheet.
The required configuration settings of the CS4245 are made in its control port registers, accessible through

the CS4245 tab of the Cirrus Logic FlexGUI softwar e.
Clock and data source selections are made through the control port of the FPGA. Basic routing selections

can be made using the CS4245 Controls tab in the GUI software application. Advanced options are acces­sible through the Board Configuration sub-tab on the Register Maps tab of the Cirrus Logic FlexGUI soft­ware. Refer to the FPGA register descriptions sections beginning on page 12.

®

configuration software.

1.4 CS8406 Digital Audio Transmitter

A complete description of the CS8406 transmitter (Figure 8 on page 21) and a discussion of the digital audio
interface are included in the CS8406 data sheet.

The CS8406 converts the PCM data generated by the CS4245 to the standard S/PDIF data stream. The
CS8406 can operate in either master or slave mode, accepts 128 Fs, 256 Fs, 384 Fs, and 512 Fs master
clocks on the OMCK input pin, and can operate in the Left-Justified, I²S, Right-Justified 16-bit, and Right­Justified 24-bit interface formats.

The most common operations of the CS8406 may be controlled via the S/PDIF I/O Controls tab in the GUI
software application. Advanced option s are accessibl e through the CS8406 sub-tab on the Register Maps
tab of the Cirrus Logic FlexGUI software.

1.5 CS8416 Digital Audio Receiver

A complete description of the CS8416 receiver (Figure 8 on page 21) and a discussion of the digital audio
interface are included in the CS8416 data sheet.

The CS8416 converts the input S/PDIF data stream into PCM da ta for the CS4245 and operates in master
or slave mode, generating eith er a 128 Fs or 256 Fs master clock on the RMCK output pin, and can operate
in the Left-Justified, I²S, Right-Justified 16-bit, and Right-Justified 24-bit interface formats.

The most common operations of the CS8416 may be controlled via the S/PDIF I/O Controls tab in the GUI
software application. Advanced option s are accessibl e through the CS8416 sub-tab on the Register Maps
tab of the Cirrus Logic FlexGUI software.

4 DS656DB1

1.6 FPGA

The FPGA handles both clock and data routing on the CDB4245. Clock and data routing selections made
via the CDB4245 Controls tab in the GUI will be handled by the FPGA with no user intervention required.
For advanced information regarding the internal re gisters and o peration of the F PGA, see sections5 and 6
beginning on page 11.

1.7 Canned Oscillators

Two canned oscillators, Y1 and Y2, are available to provide a master clock source to the CDB4245.
Each oscillator is mounted in pin sockets, allowing easy removal or replacement. The board is shipped with

12.2880 MHz crystal oscillators populated.

1.8 External Control Headers

The evaluation board has been designed to allow interfacing with e xternal systems via the headers J9, J10,
and J17.

The 8-pin, 2 row header, J10, provides access to the serial audio signals required to interf ace Serial Audio
Port 1 of the CS4245 with a DSP (see Figure 11 on page 24).

The 8-pin, 2 row header, J9, provides access to the serial audio signals required to interface Serial Audio
Port 2 of the CS4245 with a DSP (see Figure 11 on page 24).

The direction of the signals on headers J9 and J10 can be configured using the controls located within the
Board Controls group box on the CDB4245 Controls tab in the provided GUI software.

The 15-pin, 3 row header, J17, allows the user bidirectional access to the SPI/I
removing all the shunt jumpers from the “PC” position. The user ma y then choose to connect a ribbon cable
to the “EXTERNAL CONTROL” position. A single “GND” row for the ribbon cable’s ground connection is pro­vided to maintain signal integrity. Two unpopulated pull-up resistors are also available should the user
choose to use the CDB for the I

2

C power rail.

CDB4245

2

C control signals by simply

1.9 Analog Inputs

RCA connectors supply the CS4245 analog inputs through single-ended, unity gain, active or passive cir­cuits. Refer to the CS4245 data sheet for the ADC full-scale level.

A 4-pin CD-ROM type header is provided for easily connecti ng the analog outputs from a CD-ROM drive to
the analog inputs of the CS4245.

1.10 Analog Outputs

1.10.1 DAC Outputs

The CS4245 DAC analog outputs are routed through a single-p ole passive RC filter. Th e output of the filter
is connected to RCA jacks for easy evaluation.

1.10.2 Auxiliary Outputs

The CS4245 auxiliary analog outputs are routed through a two-pole active filter. The output of the filter is
connected to RCA jacks for easy evaluation.

1.11 Serial Control Port

A graphical user interface is included with the CDB4245 to allow easy manipulation of the registers in the
CS4245, CS8416, CS8406, and FPGA. See the device-specific data sheets for the CS4245, CS8416, and
CD8406 internal register descriptions. The internal register map for the FPGA is located in section 5 on page

11.
Connecting a cable to the RS-232 connector (J42) and launching the Cirrus Logic FlexGUI software (Flex-

Loader.exe) will enable the CDB4245.
Refer to “PC Software Control” on page 7 for a description of the Graphical User Interface (GUI).

DS656DB1 5

CDB4245

1.12 USB Control Port

The USB control port connector (J37) is currently unavailable.

2. SYSTEM CLOCKING

The CDB4245 implements two discrete clocking domains. One discrete domain services Serial Audio Port 1 of the
CS4245, and the other discrete domain services Serial Audio Port 2 of the CS4245. The two clock domains may
operate independently, or may be tied together. Configuration of the clocking domains is achieved using the controls
within the Board Controls group box on the CDB4245 Controls tab in the GUI software application.

2.1 Clock Domain 1

Clock domain 1 is comprised of Serial Audio Port 1 of the CS4245, the CS8406, Oscillator 1 (canned oscil­lator Y1), and the PCM1 I/O header (J10).

The master clock signal (MCLK1) may be sourced from Oscillator 1 (Y1), the PCM1 I/O header (J10), or
may be copied from the MCLK2 signal.

The sub-clock signals (SCLK1 and LRCK1) may be sourced from the CS4 245 in master mode, the CS8 406
in master mode, the PCM1 I/O header, or may be copie d from the sub-clock 2 signals (SCLK2 and LRCK2).

Configuration of clock domain 1 is achieved using the MCLK 1 Source and Subclock 1 Source controls with­in the Board Controls group box on the CDB4245 Controls tab in the GUI software application.

2.2 Clock Domain 2

Clock domain 2 is comprised of Serial Audio Port 2 of the CS4245, the CS8416, Oscillator 2 (canned oscil­lator Y2), and the PCM2 I/O header (J9).

The master clock signal (MCLK2) may be sourced from Oscillator 2 (Y2), the CS8416 recovered clock, the
PCM2 I/O header (J9), or may be copied from the MCLK1 signal.

The sub-clock signals (SCLK2 and LRCK2) may be sourced from the CS4 245 in master mode, the CS8 416
in master mode, the PCM2 I/O header, or may be copie d from the sub-clock 1 signals (SCLK1 and LRCK1).

Configuration of clock domain 2 is achieved using the MCLK 2 Source and Subclock 2 Source controls with­in the Board Controls group box on the CDB4245 Controls tab in the GUI software application.

3. SYSTEM DATA ROUTING

The CDB4245 implements comprehensive data routing capabilities. The SDIN source of both the CS4245 and the
CS8406 may be easily selected using the provided GUI software application.

3.1 CS4245 SDIN Source

The CS8416 S/PDIF receiver, the PCM2 I/O header (J9), or the CS4245 serial data output (SDOUT) may
source the serial data input of the CS4245. Configuration of the CS4 245 SDIN source is achieved using the
CS4245 SDIN Source control within the Board Controls group box on the CDB4245 Controls tab in the GUI
software application.

3.2 CS8406 SDIN Source

The CS8416 S/PDIF receiver, the PCM2 I/O header (J9), or the CS4245 serial data output (SDOUT) may
source the serial data input of the CS8406 S/PDIF transmitter. Configuration of the CS8406 SDIN source is
achieved using the CS8406 SDIN Source control within the Board Controls group box on the CDB4245 Con­trols tab in the GUI software application.

6 DS656DB1

CDB4245

4. PC SOFTWARE CONTROL

The CDB4245 is shipped with a Microsoft Windows® based graphical user interface which allows control over the
CS4245, CS8416, CS8406, and FPGA. The board control software communicates with the CDB4245 over the RS­232 interface using the PC’s COM1 port.

To use the board control software, the contents of the included CD-ROM should fir st be copied to a directory on the
PC’s local disk. If applied, the Read Only attribute should be removed from all files. Once the appropriate cable has
been connected between the CDB4245 and the host PC, load FlexLoader.exe from the Software directory. When
the software loads, all devices will be reset to their default reset state.

The GUI’s File menu provides the ability to save a nd load script file s contain ing all o f t he registe r setting s. Pr e-con­figured script files are provided for basic functionality. Refer to “Pre-Configured Script Files” on page 9 for details.

4.1 CDB4245 Controls Tab

The CDB4245 Controls tab provides a high-level intuitive interface to many of the configuration options of
the CS4245 and CDB4245. The controls within the CS4245 Controls group box (with the exception of the
AD0 and AD1 controls) control the internal registers of the CS4245. The con trols with in the Boar d Con trols
group box control the board level clock and data routing on the CDB4245.

Figure 1. CDB4245 Controls Tab

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4.2 S/PDIF I/O Controls Tab

When the CDB4245 is configured to make use of the CS8416 S/PDIF receiver or CS8406 S/PDIF transmit­ter, these devices must be c onfigured for proper operation. The S/PDIF I/O Controls tab provides a high­level intuitive interface to the most common configuration options of the CS8416 and CS8406.

CDB4245

Figure 2. S/PDIF I/O Controls Tab

8 DS656DB1

4.3 Register Maps Tab

The Register Maps tab provides low level control over the register level settings of the CS4245, CS8416,
CS8406, and FPGA. Each device is displayed on a separate tab. Register values can be modified bit-wise
or byte-wise. For bit-wise, click the appropriate push button for the desired bit. For byte-wise, the desired
hex value can be typed directly in the register address box in the register map.

CDB4245

Figure 3. Register Maps Tab

4.4 Pre-Configured Script Files

Pre-configured script files are provided with the CDB4245 to allow easy initial board bring-up. The board
configurations stored within these files are described in sections 4.4.1 - 4.4.2.

4.4.1 Oscillator Clock - ADC Ch 1 to DAC & SPDIF Out

Using the pre-configured script file named “Oscillator Clock - ADC Ch 1 to DAC & SPDIF Out.txt”, an analog
input signal applied to channel 1 of the CS4245 input multiplexer will be digitized by the ADC, transmitted
in S/PDIF format by the CS8406, and will be converted to analog by the CS4245 DAC and output through
the passive output filter and RCA jacks.

The CS4245 is in synchronous mode, with Oscillator 1 as the source of MCLK for Clock Domain 1 and 2.
The CS4245 Serial Audio Port 1 is the sub-clock master to both the CS4245 Serial Audio Port 2, and the
CS8406.

DS656DB1 9