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About This Manual
Contents
Preface
This document provides the information needed to setup and operate the
SRC4192EVM evaluation module. For a more detailed description of the
SRC4190, SRC4192, or SRC4193 products, please refer to the product data
sheets available from the Texas Instruments web site at http://www.ti.com
Support documents are listed in the sections of this guide entitled Related Documentation from Texas Instruments and Additional Documentation.
.
How to Use This Manual
Throughout this document, the abbreviation EVM and the term evaluation
module are synonymous with the SRC4192EVM. The abbreviation
SRC419x refers to the SRC4190, SRC4192. and SRC4193 family of de-
vices.
Chapter 1 provides an overview of the SRC419x family of stereo asynchro-
nous sample rate converters. The SRC4192EVM block diagram and primary features are also discussed.
Chapter 2 provides general information regarding EVM handling and unpacking, absolute operating conditions, and the default switch and jumper
configuration.
Chapter 3 is the hardware setup guide for the EVM, providing all of the necessary information needed to configure the EVM switches and jumpers for
product evaluation.
Chapter 4 includes the EVM electrical schematic, PCB layout, and the Bill
of Materials.
Information About Cautions and Warnings
This book contains cautions.
This is an example of a caution statement.
A caution statement describes a situation that could potentially
damage your software or equipment.
Contents
iii
Contents
This is an example of a warning statement.
A warning statement describes a situation that could potentially
cause harm to you
.
The information in a caution or a warning is provided for your protection.
Please read each caution and warning carefully.
Related Documentation From Texas Instruments
The following documents provide information regarding Texas Instruments
integrated circuits used in the assembly of the SRC4192EVM. These documents are available from the TI web site. The last character of the literature
number corresponds to the document revision, which is current at the time
of the writing of this User’s Guide. Newer revisions may be available from
the TI web site at http://www.ti.com/
Response Center at (800) 477–8924 or the Product Information Center at
(972) 644–5580. When ordering, identify the booklet(s) by both title and
literature number.
or call the Texas Instruments Literature
Data sheetsLiterature number
SRC4192/4193 Data SheetSBFS022
DIT4192 Data SheetSBOS229
PLL1705 Data SheetSLES046
REG1117 Data SheetSBVS001
SN74AHC32SCLS247G
SN74AHC244SCLS226I
SN74AHC1G04SCLS318L
SN74AHC1G14SCLS321K
SN74ALVC125 Data SheetSCES110E
SN74ALVC244 Data SheetSCES188B
SN74ALVC245 Data SheetSCES271B
SN74CBTLV3245A Data SheetSCDS034J
SN74LVC04A Data SheetSCAS281M
SN74LVC1G07 Data SheetSCES296K
SN74LVC1G125 Data SheetSCES223G
iv
Additional Documentation
The following documents provide information regarding selected non–TI
components, which are used in the assembly of the SRC4192EVM. These
documents are available from the corresponding manufacturers.
DocumentManufacturer
CS8414 Data SheetCirrus Logic, http://www.cirrus.com
HCM49 Series CrystalsCitizen, http://www.citizencrystal.com
SC937–02 Data SheetScientific Conversion
SC979–03 Data SheetScientific Conversion
If You Need Assistance
If you have questions regarding either the use of this evaluation module or
the information contained in the accompanying documentation, please contact the Texas Instruments Product Information Center at (972) 644–5580
or visit the TI web site at www.ti.com.
This equipment is intended for use in a laboratory test environment only. It
generates, uses, and can radiate radio frequency energy and has not been
tested for compliance with the limits of computing devices pursuant to subpart J of part 15 of FCC rules, which are designed to provide reasonable
protection against radio frequency interference. Operation of this equipment in other environments may cause interference with radio communications, in which case the user at his own expense will be required to take
whatever measures may be required to correct this interference.
All trademarks are the property of their respective owners.
This chapter provides a brief technical overview for the SRC4190, SRC4192,
and SRC4193 asynchronous sample rate converters, as well as a general
description and feature list for the SRC4192EVM.
The SRC4192 and SRC4193 are stereo asynchronous sample rate converters designed for professional and broadcast audio applications. Operation at
input and output sampling frequencies up to 212kHz is supported, with an input/output sampling ratio range of 16:1 to 1:16. Excellent dynamic range and
THD+N are achieved by employing high performance, linear phase digital filtering with better than 140dB of image rejection. The SRC4190 is a lower–cost
version of the SRC4192 with reduced performance specifications, but it is
functionally equivalent to the SRC4192 and shares the same pin configuration.
The SRC4190 and SRC4192 are both stand–alone, pin–programmed devices, with control inputs for mode, data format, mute, bypass, and low group
delay functions. The SRC4193 includes a three–wire serial peripheral interface (SPI) port, which allows access to on–chip control registers for device
function configuration. The SPI port can be easily interfaced to microprocessors or digital signal processors with synchronous serial port interfaces.
All three devices offer filtering options, which allow for lower group delay processing. These options include a low group delay mode for the interpolation
function and a direct down–sampling mode (SRC4193 only) for the decimation
function.
The audio input and output ports support standard audio data formats, as well
as a TDM interface mode. Word lengths of 24–, 20–, 18–, and 16–bits are supported. Both ports may operate in Slave mode, deriving their word (LRCK) and
bit (BCK) clocks from external input and output devices. Alternatively, one port
may be operated in Master mode while the other remains in Slave mode. In
Master mode, the LRCK and BCK clocks are derived from the reference clock
(RCKI) input. The flexible configuration of the audio ports allows connection
to a wide variety of audio data converters, digital audio interface devices, and
digital signal processors.
A bypass mode is also included. This mode allows data to be passed directly
from the audio input port to the audio output port, bypassing the sample rate
converter function. The bypass option is useful for passing through encoded
or compressed audio data, or non–audio control and status data. The input
and output port clocks must be synchronous with one another in bypass mode.
A soft mute function is included in all three devices. A digital attenuation function is available only for the SRC4193. Both soft mute and digital attenuation
functions provide artifact free operation, while allowing muting or level adjustment of the audio output signal. The mute attenuation is typically –144dB for
the SRC4192 and SRC4193, and –128dB for the SRC4190. The SRC4193
digital attenuation function is adjustable from 0dB to –127.5dB in 0.5dB steps.
A block diagram of the SRC4192 and SRC4193 is shown in Figure 1–1. The
SRC4190 offers the same functionality as the SRC4192.
1-2
The SRC4190, SRC4192, and SRC4193
Figure 1–1.Functional Block Diagram for the SRC4192 and SRC4193
LRCKI
BCKI
SDIN
MODE[2:0]
IFMT[2:0]
OFMT[1:0]
OWL[1:0]
MUTE
BYPAS
LGRP
/RST
MUTE
BYPAS
/RST
/CS
CCLK
CDATA
LRCKO
BCKO
SDOUT
TDMI
RCKI
Audio
Input
Port
Control
Logic
(SRC4192)
SPI and
Control Logic
(SRC4193)
Audio
Output
Port
Reference Clock
f
sIN
LRCKI
LRCKO
MUX
REFCLK
Rate
Estimator
Interpolation
REFCLK
/RDY
RATIO (SRC4193 only)
Filters
16f
f
f
sOUT
sOUT
sIN
(SRC4193 only)
Re–Sampler
Decimation
Filters
Direct
Down–Sampler
Power
16f
sOUT
VDD
DGND
VIO
DGND
1.2EVM Block Diagram
The block diagram for the SRC4192EVM is shown in Figure 1–2. The EVM includes buffered audio input and output ports that support I
Right Justified, and TDM data formats. These ports may be connected to external receivers and transmitters, data converters, or digital signal processors.
An on–board 96kHz receiver is provided, as well as a 192kHz transmitter. The
receiver and transmitter provide for convenient connection to both test and
commercial audio equipment supporting AES3 or S/PDIF interfaces.
The SRC4192 and DIT4192 have their own external phase locked loop circuits
for on–board clock generation. External clock inputs are also available and
provide for additional flexibility. The EVM is configured using on–board
switches and jumpers, in addition to a buffered host port, which supports the
SRC4193 SPI interface. A single +5 volt power supply is all that is needed to
power the EVM. A +3.3 volt supply is derived from the +5 volt supply using an
on–board voltage regulator.
2
S, Left Justified,
Introduction
1-3
The SRC4190, SRC4192, and SRC4193
1.3EVM Features
Key features for the SRC4192EVM include:
- Zero Insertion Force (ZIF) socket for easily interchanging SRC4190,
SRC4192 and SRC4193 devices. The Analog Devices AD1895 and
AD1896 are also supported for head–to–head testing.
- On–board or external clock generation.
- On–board receiver and transmitter supports AES3 input and output (75 Ω
BNC connections provided).
- Buffered audio input and output ports using standard dual in–line headers.
- Buffered Host Port supports connection to an external controller
(SRC4193 only).
- Operation from a single +5 volt power supply.
Figure 1–2.Functional Block Diagram for the SRC4192EVM
GND +5V
+5V
Digital
Input
75 ohm
Digital
Output
75 ohm
REG1117
External
DIT
Clock
+3.3V
Audio
Input
Port
Receiver
CS8414
Audio
Output
Port
Transmitter
DIT4192
Clock
Generator
PLL1705
SRC4192EVM
H
B
D
U
R
F
B
U
F
B
H
U
D
F
R
B
U
F
Sample
Rate
Converter
SRC4192
or
SRC4193
ZIF Socket
Provided
Clock
Generator
PLL1705
Host
H
Interface
D
R
SWDIP Switch
Port
(SRC4193 Only)
(SRC4192 Only)
External
SRC
Clock
1-4
Introduction
1-5
Chapter 2
This chapter provides information regarding SRC4192EVM handling and
unpacking, absolute operating conditions, and a description of the factory
default switch and jumper configuration.
Many of the components on the SRC4192EVM are susceptible to damage by
electrostatic discharge (ESD). Customers are advised to observe proper ESD
handling precautions when unpacking and handling the EVM, including the
use of a grounded wrist strap at an approved ESD workstation.
Caution: Failure to observe ESD handling procedures may result in
damage to EVM components.
2.2Absolute Maximum Operating Conditions
The user should be aware of the absolute maximum operating conditions for
the SRC4192EVM. Exceeding these conditions may result in damage to the
EVM. Table 2–1 summarizes the critical data points.
Table 2–1.Absolute Maximum Operating Conditions
ParameterMaximum Condition
Power Supply+5.5 VDC maximum
Audio Input and Output Ports, Host Port,
External SRC Clock, External DIT Clock
V
IH
V
IL
Digital Audio Input (Connector J2)
V
IH
V
IL
2.3Unpacking the EVM
Upon opening the SRC4192EVM package, please check to make sure that
the following items are included:
- One SRC4192EVM.
- One SRC4192IDB installed in the EVM ZIF socket.
+4.0 Volts maximum
–0.5 Volts minumum
+12 Volts maximum
–12 Volts minumum
2-2
If either of these items are missing, please contact the Texas Instruments
Product Information Center nearest you to inquire about a replacement.
2.4Default Configuration
The factory default switch and jumper settings are shown in Table 2, and result
in the following EVM configuration:
- The SRC4192 Input Port is set to Slave mode, with the CS8414 receiver
selected as the input source.
- The SRC4192 Output Port is set to Slave mode, with the DIT4192 trans-
mitter selected as the output device.
- The SRC PLL (U16) is selected as the SRC419x reference clock source
and is set to 24.576MHz.
- The SRC4192 input and output port data formats are set to 24–Bit Left
Justified.
- The CS8414 receiver output format is set to 24–Bit Left Justified
- The DIT4192 transmitter input format is set to 24–Bit Left Justified
- The DIT4192 transmitter MCLK frequency is set to 256fs, with fs = 48kHz.
Default Configuration
- The transmitter PLL (U6) is selected as the DIT4192 MCLK source and is
set to 12.288MHz.
- The DIT4192 transmitter output mode is set to stereo.
- The SRC4192 Low Group Delay, Bypass, and Mute modes are all dis-
abled.
Table 2–2.Default Switch and Jumper Settings
SW1Set To:SW3Set To:SW6Set To:SW7Set To:
M0
M1
M2
SW9Set To:SW10Set To:J8Set To:
SFS1
SFS2
SSR
~PLL
OM/~S
~IPORT
MONO
MDAT
LO
LO
LO
LO
LO
HI
LO
LO
HI
LO
LO
CLK1
CLK0
FMT0
FMT1
MODE2
MODE1
MODE0
~PORT
OFMT0
OFMT1
OWL0
OWL1
LO
HI
LO
LO
LO
LO
LO
HI
LO
LO
LO
LO
TSR
TFS2
TFS1
TPLL
1–2 (I2S/RJ)
3–4 (LJ)
LO
LO
LO
LO
LGRP
BYPAS
IFMT0
IFMT1
IFMT2
MUTE
~4193
IS/M
OPEN
SHORT
LO
LO
LO
LO
LO
LO
HI
HI
Getting Started
2-3
Chapter 3
This chapter provides a step–by–step guide to configuring the SRC4192EVM
for device evaluation. Follow the sections to walk through the setup of the
SRC4192EVM.
The SRC4192EVM requires a single +5 volt regulated dc power supply,
connected at the +5V terminal of J9. The GND terminal of J9 should be
connected to the power supply ground or common terminal. The supply
should not be connected to terminal block J9 while hot, as damage may
occur to the EVM. At no time should the power supply exceed the absolute
maximum rating.
3.2Device Selection
The ~4193 element of switch SW7 is utilized to select the device under
test.
When ~4193 is set to LO, the EVM is configured for the SRC4193. The
SRC4193 is a software–controlled device, which employs an SPI port to
access internal control registers. The SPI port is accessed through the
buffered Host Port at connector J5. The Host Port supports connection to
an external microprocessor or DSP for host control.
When ~4193 is set to HI, the EVM is configured for the SRC4190 or
SRC4192. These units are stand–alone devices and do not require an external host for operation. The user configures the EVM by means of the
on–board switches and jumpers. The Analog Devices AD1895 and AD1896
are also supported in this mode, enabling head–to–head comparison testing.
3-2
3.3Selecting the Input & Output Port Modes
The input and output ports of the SRC419x devices support seven modes
of operation. Table 3–1 summarizes the mode settings for the SRC419x
devices. In Master mode, the LRCK and BCK clocks are outputs, derived
from the reference clock (RCKI) input. In Slave mode, the LRCK and BCK
clocks are inputs, which are generated by the audio input or output device.
When ~4193 is set to HI, the port modes are selected using the MODE0,
MODE1, and MODE2 elements of switch SW10.
When ~SRC4193 is set to LO, the MODE[2:0] bits in Control Register 1 of
the SRC4193 are used to select the port modes.
Table 3–1.SRC419x Input & Output Port Mode Selection
MODE2MODE1MODE0Serial Port Mode
LOLOLOBoth Input and Output Ports are in Slave mode
Selecting the Input & Output Port Modes
LOLOHIOutput Port is in Master mode with RCKI = 128f
LOHILOOutput Port is in Master mode with RCKI = 512f
LOHIHIOutput Port is in Master mode with RCKI = 256f
HILOLOBoth Input and Output Ports are in Slave mode
HILOHIInput Port is in Master mode with RCKI = 128f
HIHILOInput Port is in Master mode with RCKI = 512f
HIHIHIInput Port is in Master mode with RCKI = 256f
s
s
s
s
s
s
Setup Guide
3-3
Selecting the Input & Output Data Formats
3.4Selecting the Input & Output Data Formats
The SRC419x devices support a flexible set of audio data formats. Table 3–2
summarizes the input and output format options for the sample rate converters. Section 3.5 of this chapter describes the format configuration for the digital
audio receiver and transmitter devices.
When ~4193 is set to HI, the IFMT0, IFMT1 and IFMT2 elements of switch
SW7 are used to select the input port data format. The OFMT0, OFMT1,
OWL0, and OWL1 elements of switch SW10 are used to select the output port
data format and word length.
When ~4193 is set to LO, Control Register 3 of the SRC4193 is used to select
the input and output data formats.
Table 3–2.SRC419x Input & Output Port Data Format Configuration
IFMT2IFMT1IFMT0Input Port Data Format
LOLOLO24–Bit Left Justified
LOLOHI24–Bit I2S
LOHILOUnused
LOHIHIUnused
HILOLO16–Bit Right Justified
HILOHI18–Bit Right Justified
HIHILO20–Bit Right Justified
HI
HIHI24–Bit Right Justified
OFMT1OFMT0Output Port Data Format
LOLOLeft Justified
LOHII2S
HI
HI
OWL1OWL0Output Port Data Word Length
LOLO24–Bits
LOHI20–Bits
LO
HI
TDM
Right Justified
3-4
HI
HI
LO
HI
18–Bits
16–Bits
Selecting an Input Source and an Output Port
3.5Selecting an Input Source and an Output Port
The ~IPORT element of switch SW9 is utilized to select the input source.
When ~IPORT is set to LO, the buffered Audio Input Port at connector J1 is
selected as the input source. This port is designed to interface to devices that
support Left Justified, Right Justified, and I
When selecting the Audio Input Port as the input source, the IS/~M element
of switch SW7 must be set to match the mode of the SRC419x input port (Master or Slave), as described in Section 3.3 of this chapter. The data format of
the external audio device must be set to match the format of the Audio Input
Port.
When ~IPORT is set to HI, connector J2 at the input of the CS8414 digital audio
receiver (U1) is selected as the input source. This port is designed to interface
to digital audio signal generators and devices that output AES3 formatted digital audio data. This includes the S/PDIF outputs of CD and DVD players.
When selecting the digital audio receiver (U1) as the input source, the IS/~M
element of switch SW7 must be set to LO (Slave mode), and the SRC419x input port must be set to Slave mode, as described in Section 3.3 of this chapter.
The output data format of the digital audio receiver must be selected using
switch SW1 and jumper block J8. The receiver output format must match the
input data format of the SRC419x device, as described in Section 3.4 of this
chapter. Table 3–3 summarizes the configuration of switch SW1 and jumper
block J8 for the supported data formats.
2
S formatted digital audio data.
Table 3–3.Digital Audio Receiver Output Data Format Configuration
M2M1M0J8Data Format
LO
LO
HI
HI
The ~PORT element of switch SW10 is utilized to select the output port.
When ~PORT is set to LO, the buffered Audio Output Port at connector J3 is
selected as the output port. This port is designed to interface to devices that
support Left Justified, Right Justified, and I
When selecting the Audio Output Port as the output port, the OM/~S element
of switch SW9 must be set to match the mode of the SRC419x output port
(Master or Slave), as described in Section 3.3 of this chapter. The data format
of the external audio device must be set to match the format of the Audio Output Port.
LO
HI
LO
HI
LO
LO
HI
LO
Short 3–4 (LJ)
Short 1–2 (I2S/RJ)
Short 1–2 (I2S/RJ)
Short 1–2 (I2S/RJ)
2
S formatted digital audio data.
Left Justified, 16– to 24–Bits
Philips I
Right Justified, 16–Bits
Right Justified, 18–Bits
2
S, 16– to 24–Bits
Setup Guide
3-5
Selecting an Input Source and an Output Port
When ~PORT = HI, the output of the DIT4192 digital audio transmitter (U5) at
connector J4 is selected as the output port. This port is designed to interface
to digital audio signal analyzers and devices that accept AES3 formatted digital audio data. This includes the S/PDIF inputs of A/V receivers and digital recording devices.
When selecting the digital au dio transmitter (U5) as the output port, the setting
of the OM/~S element of switch SW9 will correctly set the Master or Slave
mode for both the SRC419x and DIT4192 devices. The input data format of
the transmitter must be selected using the FMT0 and FMT1 elements of switch
SW3. The format must match the output data format of the SRC419x device,
as described in Section 3.4 of this chapter. Table 3–4 summarizes the transmitter format configuration options using switch SW3.
Table 3–4.Digital Audio Transmitter Input Data Format Configuration
FMT1FMT0Data Format
LO
LO
HI
HI
LO
HI
LO
HI
Left Justified, 16– to 24–Bits
Philips I
Right Justified, 24–Bits
Right Justified, 16–Bits
2
S, 16– to 24–Bits
3-6
Selecting the SRC419x Reference Clock Source and Frequency
3.6Selecting the SRC419x Reference Clock Source and Frequency
The ~PLL element of switch SW9 is used to select the reference clock source
for the SRC419x. The reference clock input is utilized by the SRC419x rate estimator, as well as the input or output port when configured in Master mode.
The Master mode port derives the LRCK and BCK clock outputs from the reference clock input.
When ~PLL is set to LO, the PLL1705 (U16) is selected as the reference clock
source for the SRC419x. Table 3–5 summarizes the output rate selections for
the PLL1705.
When ~PLL is set to HI, the EXT SRC CLK input (J6) is selected as the reference clock input. The EXT SRC CLK input supports +3.3V CMOS external
clock sources with frequencies up to 50MHz.
Table 3–5.PLL Reference Clock Selection for the SRC419x
SSRSFS2SFS1PLL Output Rate (MHz)
LOLOLO12.288
LOLOHI11.2896
LOHILO8.192
LOHIHIReserved
HILOLO24.576
HILOHI22.5792
HIHILO16.384
HI
HIHIReserved
Setup Guide
3-7
Selecting the DIT4192 Master Clock Source and Frequency
3.7Selecting the DIT4192 Master Clock Source and Frequency
The OM/~S element of switch SW9 and the ~TPLL element of SW6 are used
to select the master clock source for the DIT4192 digital audio transmitter. The
master clock (or MCLK) frequency determines the output frame (or sampling)
rate of the transmitter, in addition to determining the SYNC and SCLK output
rates when the DIT4192 is configured in Master mode. Table 3–6 summarizes
the DIT4192 master clock source options.
When OM/~S is set to HI (that is, the SRC419x output port is the Master and
the DIT4192 is a Slave), the reference clock source for the SRC419x will also
be used as the master clock source for the DIT4192. This ensures synchronization between the SRC419x output port and DIT4192 audio serial port.
Table 3–6.DIT4192 Master Clock Selection
~TPLLOM/~SDIT4192 MCLK Source
LOLOPLL1705 (U6)
HILOEXT DIT CLK (J7)
X
X = Don’t Care
HISRC419x Ref Clock
When OM/~S is set to LO (that is, the SRC419x output port is a Slave and the
DIT4192 is the Master), the ~TPLL element of switch SW6 is utilized to select
the DIT4192 master clock source, as shown in Table 3–6.
When the PLL1705 (U6) is selected as the master clock source, the TSR,
TFS1, and TFS2 elements of switch SW6 are utilized to select the PLL output
rate. Table 3–7 summarizes the PLL output rate options.
Table 3–7.PLL Master Clock Source Selection for the DIT4192
Selecting the DIT4192 Master Clock Source and Frequency
When the EXT DIT CLK input at connector J7 is selected as the master clock
source, the device will support an external +3.3V CMOS logic level clock
source with frequencies up to 25MHz.
In addition to DIT4192 master clock source selection, the DIT4192 master
clock divider must be selected using the CLK0 and CLK1 elements of switch
SW3. The master clock source frequency will be divided by the factor listed in
Table 3–8 to determine the transmitter output frame rate, as well as the SYNC
and SCLK clock rate when the DIT4192 is configured in Master mode.
Table 3–8.PLL Master Clock Selection for the DIT4192
CLK1CLK0DIT4192 MCLK Divider
LOLODivide by 128
LOHIDivide by 256
HILODivide by 384
HI
HIDivide by 512
Setup Guide
3-9
Miscellaneous Functions
3.8Miscellaneous Functions
This section provides information regarding several SRC419x and DIT4192
functions not described previously in this chapter.
Low group delay operation is controlled using the LGRP element of switch
SW7, or by the LGRP bit in Control Register 2 when using the SRC4193. The
low group delay option reduces the overall latency of the interpolation filter by
32/f
, where f
sIN
rizes Low Group Delay operation.
Table 3–9.Low Group Delay Configuration
is the input sampling rate in hertz (Hz). Table 3–9 summa-
sIN
LGRPLow Group Delay Mode
LODisabled
HIEnabled
Bypass mode operation is controlled using the BYPAS element of switch SW7,
or by the BYPAS bit in Control Register 1 when using the SRC4193. When Bypass mode is enabled, the audio data is passed directly from the input port to
the output port without sample rate conversion. This process is useful for passing through encoded audio or non–audio data. In Bypass mode, the mute, dithering, and digital attenuation (SRC4193 only) functions are not available.
Table 3–10 summarizes Bypass mode operation.
Table 3–10.Bypass Mode Configuration
BYPASBypass Mode
LODisabled
HIEnabled
3-10
The Mute function is controlled using the MUTE element of switch SW7, or by
the MUTE bit of Control Register 1 when using the SRC4193. This function
employs a soft mute technique, which provides for artifact–free muting of the
SRC419x output port. Table 3–11 summarizes Mute function operation.
Table 3–11.Mute Function Configuration
MUTESoft Mute Function
LODisabled
HIEnabled
A Direct Down–Sampling option is available only when using the SRC4193.
It is accessed using the DFLT bit in Control Register 2. Refer to the
SRC4192/4193 data sheet for more details regarding the use of this mode.
The DIT4192 digital audio transmitter supports Single Channel Double Frequency operation, also referred to as Mono mode in the DIT4192 data sheet.
In this mode, the DIT4192 output frame rate is one half the input SYNC clock
rate, with two consecutive samples of a single channel replacing the Left and
Right channel samples of the normal Stereo mode transmission. This mode
is useful when testing 176.4kHz and 192kHz sampling rates on an Audio Precision System T wo Cascade/Cascade Plus Dual Domain system, configured in
Dual Channel mode. Only one channel at a time may be tested in this fashion.
Miscellaneous Functions
The MONO and MDA T elements of switch SW9 are utilized to configure Mono
mode operation. Table 3–12 summarizes the MONO and MDAT options.
Table 3–12.DIT4192 Mono Mode Configuration
MonoStereo/Mono Mode Operation
LOStereo
HIMono
MDATAudio/Channel Status Data Selection
LOLeft Channel Audio Data / Channel A
CS Data
HIRight Channel Audio Data / Channel B
CS Data
Setup Guide
3-11
Reset Functions
3.9Reset Functions
The SRC4192EVM includes three reset switches, one each for the SRC419x
(SW8), the CS8414 receiver (SW2), and the DIT4192 transmitter (SW4). Each
switch is a momentary contact, normally open push–button with 10kΩ pull–up
resistors to the +3.3V supply. To reset a device, momentarily press, then release, the corresponding reset switch. This allows the user to reset the devices
at will, if necessary or desired.
3-12
Chapter 4
! " #
This chapter provides the electrical and physical layout information for the
SRC4192EVM. The bill of materials is included for component and
manufacturer reference.
The schematic diagram is shown, beginning on page 4-2. The printed circuit board layouts are shown on pages 4-4 through 4-6. The bill of materials is shown starting on page 4-7.
The complete electrical schematics of for the SRC4192EVM are shown in
Figure 4–1 and Figure 4–2.
Figure 4–1.SRC4192EVM Schematic Diagram (page 1 of 2)
4-2
Figure 4–2.SRC4192EVM Schematic Diagram (page 2 of 2)
Schematic
Schematic, PCB Layout and Bill of Materials
4-3
Component Layout
4.2Component Layout
The printed circuit board plots for the SRC4192EVM are shown in Figure 4–3
through Figure 4–5. The PCB is a two–layer board, with most components
mounted on the top (or component) side. The power supply bypass capacitors
for U15 are mounted on the bottom (or solder) side of the PCB.