Texas Instruments TLV320AIC32EVM, TLV320AIC32EVM-PDK User Manual
TLV320AIC32EVM and TLV320AIC32EVM-PDK User's
This user's guide describes the characteristics, operation, and use of the
TLV320AIC32EVM, both by itself and as part of the TLV320AIC32EVM-PDK. This
evaluation module (EVM) is a complete stereo audio codec with several inputs and
outputs, extensive audio routing, mixing and effects capabilities. A complete circuit
description, schematic diagram and bill of materials are also included.
The following related documents are available through the Texas Instruments web site
at www.ti.com .
EVM-Compatible Device Data Sheets
Device Literature Number
TLV320AIC32 SLAS479
TAS1020B SLES025
REG1117-3.3 SBVS001
TPS767D318 SLVS209
SN74LVC125A SCAS290
SN74LVC1G125 SCES223
SN74LVC1G07 SCES296
User's Guide
SBAU113 – November 2005
Guide
Contents
1 EVM Overview ............................................................................................................... 2
2 Analog Interface .............................................................................................................. 3
3 Digital Interface .............................................................................................................. 4
4 Power Supplies .............................................................................................................. 5
5 EVM Operation ............................................................................................................... 6
6 Kit Operation ................................................................................................................. 7
7 EVM Bill of Materials ....................................................................................................... 36
Appendix A TLV320AIC32EVM Schematic .................................................................................. 40
Appendix B USB-MODEVM Schematic ...................................................................................... 41
List of Figures
1 TLV320AIC32EVM-PDK Block Diagram ................................................................................. 8
2 Default Software Screen .................................................................................................. 10
3 Audio Generator Screen .................................................................................................. 12
4 Audio Analyzer Screen ................................................................................................... 13
5 Audio Input Tab ............................................................................................................ 14
6 Audio Interface Tab ....................................................................................................... 16
7 Clocks Tab ................................................................................................................. 17
I2S, I2C are trademarks of Koninklijke Philips Electronics N.V.
Windows is a trademark of Microsoft Corporation.
SPI is a trademark of Motorola, Inc.
LabView is a trademark of National Instruments.
All trademarks are the property of their respective owners.
SBAU113 – November 2005 TLV320AIC32EVM and TLV320AIC32EVM-PDK User's Guide 1
www.ti.com
EVM Overview
8 AGC Tab .................................................................................................................... 19
9 Filters Tab .................................................................................................................. 20
10 ADC Highpass Filter Settings ............................................................................................ 21
11 Enabling Filters ............................................................................................................ 21
12 Shelf Filters ................................................................................................................. 22
13 EQ Filters ................................................................................................................... 22
14 Analog Simulation Filters ................................................................................................. 23
15 Preset Filters ............................................................................................................... 23
16 De-emphasis Filters ....................................................................................................... 24
17 User Filters ................................................................................................................. 25
18 3D Effect Settings ......................................................................................................... 25
19 DAC/Line Outputs Tab .................................................................................................... 26
20 Output Stage Configuration Tab ......................................................................................... 28
21 High Power Outputs Tab ................................................................................................. 29
22 Command Line Interface Tab ............................................................................................ 30
23 File Menu ................................................................................................................... 31
List of Tables
1 Analog Interface Pinout ..................................................................................................... 3
2 Alternate Analog Connectors ............................................................................................... 4
3 Digital Interface Pinout ...................................................................................................... 4
4 Power Supply Pin Out ....................................................................................................... 5
5 List of Jumpers ............................................................................................................... 7
6 USB-MODEVM SW2 Settings ............................................................................................. 9
7 USB Control Endpoint HIDSETREPORT Request .................................................................... 31
8 Data Packet Configuration ................................................................................................ 32
9 GPIO Pin Assignments .................................................................................................... 34
10 TLV320AIC32EVM Bill of Materials ...................................................................................... 37
11 USB-MODEVM Bill of Materials .......................................................................................... 38
1 EVM Overview
1.1 Features
1.2 Introduction
• Full-featured evaluation board for the TLV320AIC32 stereo audio codec.
• Modular design for use with a variety of digital signal processor (DSP) and microcontroller interface
boards.
The TLV320AIC32EVM-PDK is a complete evaluation kit, which includes a universal serial bus
(USB)-based motherboard and evaluation software for use with a personal computer running Microsoft
Windows™ operating systems (Win2000 or XP).
The TLV320AIC32EVM is in Texas Instruments' modular EVM form factor, which allows direct evaluation
of the device performance and operating characteristics, and eases software development and system
prototyping. This EVM is compatible with the 5-6K Interface Evaluation Module (SLAU104 ) and the
HPA-MCUINTERFACE (SLAU106 ) from Texas Instruments and additional third-party boards that support
the TI Modular EVM format.
The TLV320AIC32EVM-PDK is a complete evaluation/demonstration kit, which includes a USB-based
motherboard called the USB-MODEVM Interface board and evaluation software for use with a personal
computer running Microsoft Windows operating systems.
TLV320AIC32EVM and TLV320AIC32EVM-PDK User's Guide2 SBAU113 – November 2005
www.ti.com
2 Analog Interface
Analog Interface
For maximum flexibility, the TLV320AIC32EVM is designed for easy interfacing to multiple analog sources.
Samtec part numbers SSW-110-22-F-D-VS-K and TSM-110-01-T-DV-P provide a convenient 10-pin dual
row header/socket combination at J1 and J2. These headers/sockets provide access to the analog input
and output pins of the device. Consult Samtec at www.samtec.com or call 1-800-SAMTEC-9 for a variety
of mating connector options. Table 1 summarizes the analog interface pinout for the TLV320AIC32EVM.
Table 1. Analog Interface Pinout
PIN NUMBER SIGNAL DESCRIPTION
J1.1 HPLCOM High Power Output Driver (Left Minus or Multifunctional)
J1.2 HPLOUT High Power Output Driver (Left Plus)
J1.3 HPRCOM High Power Output Driver (Right Minus or Multifunctional)
J1.4 HPROUT High Power Output Driver (Right Plus)
J1.5 LINE1L Left Input 1
J1.6 LINE1R Right Input 1
J1.7 LINE2L Left Input 2
J1.8 LINE2R Right Input 2
J1.9 AGND Analog Ground
J1.10 MIC3L Left Input 3
J1.11 AGND Analog Ground
J1.12 MIC3R Right Input 3
J1.13 AGND Analog Ground
J1.14 MICBIAS Microphone Bias Voltage Output
J1.15 NC Not Connected
J1.16 NC Not Connected
J1.17 AGND Analog Ground
J1.18 NC Not Connected
J1.19 AGND Analog Ground
J1.20 NC Not Connected
J2.1 NC Not Connected
J2.2 NC Not Connected
J2.3 NC Not Connected
J2.4 NC Not Connected
J2.5 NC Not Connected
J2.6 NC Not Connected
J2.7 LEFT_LOP Left Line Output (Plus)
J2.8 LEFT_LOM Left Line Output (Minus)
J2.9 AGND Analog Ground
J2.10 RIGHT_LOP Right Line Output (Plus)
J2.11 AGND Analog Ground
J2.12 RIGHT_LOM Right Line Output (Minus)
J2.13 AGND Analog Ground
J2.14 NC Not Connected
J2.15 NC Not Connected
J2.16 NC Not Connected
J2.17 AGND Analog Ground
J2.18 NC Not Connected
J2.19 AGND Analog Ground
J2.20 NC Not Connected
SBAU113 – November 2005 TLV320AIC32EVM and TLV320AIC32EVM-PDK User's Guide 3
www.ti.com
Digital Interface
3 Digital Interface
In addition to the analog headers, the analog inputs and outputs may also be accessed through alternate
connectors, either screw terminals or audio jacks. The stereo microphone input is also tied to J8 and the
stereo headphone output (the HP set of outputs) is available at J9.
Table 2 summarizes the screw terminals available on the TLV320AIC32EVM.
Table 2. Alternate Analog Connectors
DESIGNATOR PIN 1 PIN 2 PIN3
J6 AGND LINE1R LINE1L
J7 MIC3L MIC3R AGND
J10 (+) LEFT_LOP (-) LEFT_LOM
J11 (+) RIGHT_LOP (-) RIGHT_LOM
J12 (+) HPLOUT (-) HPLCOM AGND
J13 (+) HPROUT (-) HPRCOM AGND
J14 AGND LINE2R LINE2L
The TLV320AIC32EVM is designed to easily interface with multiple control platforms. Samtec part
numbers SSW-110-22-F-D-VS-K and TSM-110-01-T-DV-P provide a convenient 10-pin dual row
header/socket combination at J4 and J5. These headers/sockets provide access to the digital control and
serial data pins of the device. Consult Samtec at www.samtec.com or call 1-800- SAMTEC-9 for a variety
of mating connector options. Table 3 summarizes the digital interface pinout for the TLV320AIC32EVM.
Table 3. Digital Interface Pinout
PIN NUMBER SIGNAL DESCRIPTION
J4.1 NC Not Connected
J4.2 NC Not Connected
J4.3 NC Not Connected
J4.4 DGND Digital Ground
J4.5 NC Not Connected
J4.6 NC Not Connected
J4.7 NC Not Connected
J4.8 RESET INPUT Reset signal input to AIC32EVM
J4.9 NC Not Connected
J4.10 DGND Digital Ground
J4.11 NC Not Connected
J4.12 NC Not Connected
J4.13 NC Not Connected
J4.14 AIC32 /RESET Reset
J4.15 NC Not Connected
J4.16 SCL I2C Serial Clock
J4.17 NC Not Connected
J4.18 DGND Digital Ground
J4.19 NC Not Connected
J4.20 SDA I2C Serial Data Input/Output
J5.1 NC Not Connected
J5.2 NC Not Connected
J5.3 BCLK Audio Serial Data Bus Bit Clock (Input/Output)
J5.4 DGND Digital Ground
TLV320AIC32EVM and TLV320AIC32EVM-PDK User's Guide4 SBAU113 – November 2005
www.ti.com
Table 3. Digital Interface Pinout (continued)
PIN NUMBER SIGNAL DESCRIPTION
J5.5 NC Not Connected
J5.6 NC Not Connected
J5.7 WCLK Audio Serial Data Bus Word Clock (Input/Output)
J5.8 NC Not Connected
J5.9 NC Not Connected
J5.10 DGND Digital Ground
J5.11 DIN Audio Serial Data Bus Data Input (Input)
J5.12 NC Not Connected
J5.13 DOUT Audio Serial Data Bus Data Output (Output)
J5.14 NC Not Connected
J5.15 NC Not Connected
J5.16 SCL I2C Serial Clock
J5.17 MCLK Master Clock Input
J5.18 DGND Digital Ground
J5.19 NC Not Connected
J5.20 SDA I2C Serial Data Input/Output
Note that J5 comprises the signals needed for an I2S™ serial digital audio interface; the control interface
( I2C™ and RESET) signals are routed to J4. I2C is actually routed to both connectors; however, the device
is connected only to J4.
Power Supplies
4 Power Supplies
J3 provides connection to the common power bus for the TLV320AIC32EVM. Power is supplied on the
pins listed in Table 4 .
The TLV320AIC32EVM-PDK motherboard (the USB-MODEVM Interface board) supplies power to J3 of
the TLV320AIC32EVM. Power for the motherboard is supplied either through its USB connection or via
terminal blocks on that board.
4.1 Stand-Alone Operation
When used as a stand-alone EVM, power can be applied to J3 directly. The user must be sure to
reference the supplies to the appropriate grounds on that connector.
Table 4. Power Supply Pin Out
SIGNAL PIN NUMBER SIGNAL
NC J3.1 J3.2 NC
+5VA J3.3 J3.4 NC
DGND J3.5 J3.6 AGND
DVDD (1.8V) J3.7 J3.8 NC
IOVDD (3.3V) J3.9 J3.10 NC
CAUTION
Verify that all power supplies are within the safe operating limits shown on
the TLV320AIC32 data sheet before applying power to the EVM.
SBAU113 – November 2005 TLV320AIC32EVM and TLV320AIC32EVM-PDK User's Guide 5
www.ti.com
EVM Operation
4.2 USB-MODEVM Interface Power
The USB-MODEVM Interface board can be powered from several different sources:
• USB
• 6VDC-10VDC AC/DC external wall supply (not included)
• Lab power supply
When powered from the USB connection, JMP6 should have a shunt from pins 1–2 (this is the default
factory configuration). When powered from 6V-10VDC, either through the J8 terminal block or the J9
barrel jack, JMP6 should have a shunt installed on pins 2-3. If power is applied in any of these ways,
onboard regulators generate the required supply voltages and no further power supplies are necessary.
If lab supplies are used to provide the individual voltages required by the USB-MODEVM Interface, JMP6
should have no shunt installed. Voltages are then applied to J2 (+5VA), J3 (+5VD), J4 (+1.8VD), and J5
(+3.3VD). The +1.8VD and +3.3VD can also be generated on the board by the onboard regulators from
the +5VD supply; to enable this configuration, the switches on SW1 need to be set to enable the
regulators by placing them in the ON position (lower position, looking at the board with text reading
right-side up). If +1.8VD and +3.3VD are supplied externally, disable the onboard regulators by placing
SW1 switches in the OFF position.
Each power supply voltage has an LED (D1-D7) that lights when the power supplies are active.
5 EVM Operation
This section provides information on the analog input and output, digital control, and general operating
conditions for the TLV320AIC32EVM.
5.1 Analog Input
The analog input sources can be applied directly to J1 (top or bottom side) or through signal conditioning
modules available for the modular EVM system.
The analog inputs may also be accessed through J8 and and screw terminals J6, J7, and J14.
5.2 Analog Output
The analog outputs from the TLV320AIC32 are available on J1 and J2 (top or bottom). They also may be
accessed through J9, J10, J11, J12, and J13.
5.3 Digital Control
The digital control signals can be applied directly to J4 and J5 (top or bottom side). The modular
TLV320AIC32EVM can also be connected directly to a DSP interface board, such as the
5-6KINTERFACE or HPA-MCUINTERFACE, or to the USB-MODEVM Interface board if purchased as part
of the TLV320AIC32EVM-PDK. See the product folder for this EVM or the TLV320AIC32 for a current list
of compatible interface and/or accessory boards.
TLV320AIC32EVM and TLV320AIC32EVM-PDK User's Guide6 SBAU113 – November 2005
www.ti.com
5.4 Default Jumper Locations
Table 5 lists the jumpers found on the EVM and their respective factory default conditions.
JUMPER POSITION JUMPER DESCRIPTION
JMP1 Installed Connects analog and digital grounds
JMP2 Open Selects on-board EEPROM as firmware source
JMP3 Installed Connects on-board Mic to Left Microphone Input
JMP4 Installed Connects on-board Mic to Right Microphone Input
JMP5 Installed Provides a means of measuring IOVDD current
JMP6 Installed Provides a means of measuring DVDD current
JMP7 Installed Provides a means of measuring DRVDD current
JMP8 Installed Provides a means of measuring AVDD_DAC current
JMP9 Open When installed, allows the USB-MODEVM to hardware reset the device under user
JMP10 2-3 When connecting 2-3, mic bias comes from the MICBIAS pin on the device; when
JMP11 Installed When installed, shorts across the output capacitor on HPLOUT; remove this jumper if
JMP12 Installed When installed, shorts HPLCOM and HPRCOM. Use only if these signals are set to
JMP13 Installed When installed, shorts across the output capacitor on HPLCOM; remove this jumper if
JMP14 Installed When installed, shorts across the output capacitor on HPROUT; remove this jumper if
JMP15 Installed When installed, shorts across the output capacitor on HPRCOM; remove this jumper if
Kit Operation
Table 5. List of Jumpers
DEFAULT
control
connecting 1-2, mic bias is supplied from the power supply through a resistor, which
the user must install.
using AC-coupled output drive
constant VCM.
using AC-coupled output drive
using AC-coupled output drive
using AC-coupled output drive
6 Kit Operation
This section provides information on using the TLV320AIC32EVM-PDK, including set up, program
installation, and program usage.
SBAU113 – November 2005 TLV320AIC32EVM and TLV320AIC32EVM-PDK User's Guide 7
www.ti.com
EVM Position 2
EVM Position 1
TLV320AIC32EVM
Control Interface
TLV320AIC32
TAS1020B
USB 8051
Microcontroller
USB
SPI, I C
2
I S, AC97
2
Audio Interface
Kit Operation
6.1 TLV320AIC32EVM-PDK Block Diagram
A block diagram of the TLV320AIC32EVM-PDK is shown in Figure 1 . The evaluation kit consists of two
circuit boards connected together. The motherboard is designated as the USB-MODEVM Interface board,
while the daughtercard is the TLV320AIC32EVM described previously in this manual.
Figure 1. TLV320AIC32EVM-PDK Block Diagram
The USB-MODEVM Interface board is intended to be used in USB mode, where control of the installed
EVM is accomplished using the onboard USB controller device. Provision is made, however, for driving all
the data buses (I2C, SPI™, I2S/AC97) externally. The source of these signals is controlled by SW2 on the
USB-MODEVM. Refer to Table 6 for details on the switch settings.
8 TLV320AIC32EVM and TLV320AIC32EVM-PDK User's Guide SBAU113 – November 2005
www.ti.com
Table 6. USB-MODEVM SW2 Settings
SW-2 SWITCH
NUMBER LABEL SWITCH DESCRIPTION
1 A0 USB-MODEVM EEPROM I2C Address A0
ON: A0 = 0
OFF: A0 = 1
2 A1 USB-MODEVM EEPROM I2C Address A1
ON: A1 = 0
OFF: A1 = 1
3 A2 USB-MODEVM EEPROM I2C Address A2
ON: A2 = 0
OFF: A2 = 1
4 USB I2S I2S Bus Source Selection
ON: I2S Bus connects to TAS1020
OFF: I2S Bus connects to USB-MODEVM J14
5 USB MCK I2S Bus MCLK Source Selection
ON: MCLK connects to TAS1020
OFF: MCLK connects to USB-MODEVM J14
6 USB SPI SPI Bus Source Selection
ON: SPI Bus connects to TAS1020
OFF: SPI Bus connects to USB-MODEVM J15
7 USB RST RST Source Selection
ON: EVM Reset Signal comes from TAS1020
OFF: EVM Reset Signal comes from USB-MODEVM J15
8 EXT MCK External MCLK Selection
ON: MCLK Signal is provided from USB-MODEVM J10
OFF: MCLK Signal comes from either selection of SW2-5
Kit Operation
For use with the TLV320AIC32EVM, SW-2 positions 1 through 7 should be set to ON, while SW-2.8
should be set to OFF.
6.2 Installation
Ensure that the TLV320AIC32EVM is installed on the USB-MODEVM Interface board, aligning J1, J2, J3,
J4, J5 with the corresponding connectors on the USB-MODEVM.
Place the CD-ROM into your PC CD-ROM drive. Locate the Setup program on the disk, and start it. The
Setup program will install the TLV320AIC32 Evaluation software on your PC.
After the main program is installed, the NI-VISA Runtime installer will automatically run. This software
allows the program to communicate with the USB-MODEVM.
When the installation completes, click Finish on the TLV320AIC32EVM installer window. You may be
prompted to restart your computer.
When installation is complete, attach a USB cable from your PC to the USB-MODEVM Interface board. As
configured at the factory, the board will be powered from the USB interface, so the power indicator LEDs
on the USB-MODEVM should light. Once this connection is established, launch the TLV320AIC32
Evaluation software on your PC.
SBAU113 – November 2005 TLV320AIC32EVM and TLV320AIC32EVM-PDK User's Guide 9
Kit Operation
The software should automatically find the TLV320AIC32EVM, and a screen similar to the one in Figure 2
should appear.
www.ti.com
6.3 USB-MODEVM Interface Board
The simple diagram shown in Figure 1 shows only the basic features of the USB-MODEVM Interface
board. The board is built around a TAS1020B streaming audio USB controller with an 8051-based core.
The board features two positions for modular EVMs, or one double-wide serial modular EVM may be
installed.
Since the TLV320AIC32EVM is a double-wide modular EVM, it is installed with connections to both EVM
positions, which connects the TLV320AIC32 digital control interface to the I2C port realized using the
TAS1020B, as well as the TAS1020B digital audio interface.
In the factory configuration, the board is ready to use with the TLV320AIC32EVM. To view all the functions
and configuration options available on the USB-MODEVM board, see the USB-MODEVM Interface Board
schematic in Appendix B.
TLV320AIC32EVM and TLV320AIC32EVM-PDK User's Guide10 SBAU113– November 2005
Figure 2. Default Software Screen
www.ti.com
6.4 Program Description
After the TLV320AIC32EVM-PDK software installation (described in Section 6.2 ) is complete, evaluation
and development with the TLV320AIC32 can begin.
6.5 Indicators and Main Screen Controls
Figure 2 illustrates the indicators and controls near the top of the software screen display, and a large
tabbed interface below. This section discusses the controls above this tabbed section.
At the top left of the screen is an Interface indicator. The TLV320AIC32 has an I2C interface. The
indicator is lit after the program begins.
To the right of the Interface indicator is a group box called Firmware. This box indicates where the
firmware being used is operating from—in this release, the firmware is on the USB-MODEVM, so you
should see USB-MODEVM in the box labeled Located On:. The version of the firmware appears in the
Version box below this.
To the right, the next group box contains controls for resetting the TLV320AIC32. A software reset can be
done by writing to a register in the TLV320AIC32; the writing is accomplished by pushing the button
labeled Software Reset. The TLV320AIC32 also may be reset by toggling a pin on the TLV320AIC32,
which is done by pushing the Hardware Reset button.
In order to perform a hardware reset, the RESET jumper (JMP9) must be
installed and SW2-7 on the USB-MODEVM must be turned OFF. Failure to
do either of these steps results in not generating a hardware reset or
causing unstable operation of the EVM, which may require cycling power
to the USB-MODEVM.
Kit Operation
CAUTION
6.5.1 Audio Analyzer
The ADC Overflow and DAC Overflow indicators light when the overflow flags are set in the
TLV320AIC32. These indicators, as well as the other indicators on this panel, update only when the
software's front panel is inactive, once every 20ms. Below these indicators are other indicators that show
when the AGC noise threshold is exceeded. To the far right on this screen, the short-circuit indicators
show when a short-circuit condition is detected, if this feature has been enabled. Below the short-circuit
indicators is a bar graph that shows the amount of gain which has been applied by the AGC, and
indicators that light when the AGC is saturated.
Near the left side of the screen is a button labeled Audio Analyzer; this button can be set to ON or OFF.
Pressing the button to turn it ON opens another window (see Figure 3 ). This feature provides the ability to
generate signals to be sent to the TLV320AIC32 DACs, as well as viewing and analyzing signals read by
the TLV320AIC32 ADCs. This ability to view and process the real-time streaming USB audio is a
demanding task. Use of the Audio Analyzer feature requires a PC with at least 512MB of memory and
reasonable processor speed (> 1GHz); computers with inadequate resources could still use the Audio
Analyzer to generate signals for the DACs, but will be unable to process signals from the ADCs because
the FFT, distortion analysis, and signal-to-noise ratio analysis will not be able to keep up with the data
processing requirements.
The Audio Analyzer features two tabs. The front tab, shown in Figure 3 and titled Generator, creates
digital waveforms to send to the DACs. When first started, the function will be set to SNR (Output Zeros)
which feeds only zero codes to the DAC. This function is commonly performed to test for the noise floor of
the DAC.
The second function available is THD (-1dB sinewave). This function sends a sinewave at a coherent
frequency to the 44.1kHz sample rate to the DACs; this function is commonly used for testing THD+N.
These first two functions do not require any further settings; therefore, the frequency and amplitude knobs
below the function selector are not used. Selecting a function of Function Generator allows the choice of
waveform shape by using the pull-down menu next to the function selector, and the frequency and
amplitude of that signal can be varied using the knobs below.
SBAU113 – November 2005 TLV320AIC32EVM and TLV320AIC32EVM-PDK User's Guide 11
www.ti.com
Kit Operation
The output waveforms for both left and right channels are displayed in the graph at the bottom of the
screen in Figure 3 .
TLV320AIC32EVM and TLV320AIC32EVM-PDK User's Guide12 SBAU113 – November 2005
Figure 3. Audio Generator Screen
www.ti.com
The second tab, titled Analyzer (Figure 4 ), handles the display and analysis of data from the ADCs.
Kit Operation
The analyzer screen features a graph of the input signals, both left and right channels, in a time domain
display at the top of the screen, and in the frequency domain (FFT) at the bottom of the screen.
SBAU113 – November 2005 TLV320AIC32EVM and TLV320AIC32EVM-PDK User's Guide 13
Figure 4. Audio Analyzer Screen
www.ti.com
Kit Operation
Next to the time domain plots, calculated values of SINAD, SNR, and THD are shown. These values are
all expressed in dB relative to the full-scale of the TLV320AIC32. Note that the SNR number shown is
A-weighted.
In Figure 4 , a sine wave generated by the TLV320AIC32 DACs is fed through the high power drivers and
back into the ADC; then the resulting FFTs can be seen. Note that this sequence is a full analog loopback
test case, so the measured numbers show the combined performance of the DAC, drivers, and ADC.
There is also no post-DAC filtering; as noted in the data sheet, this may degrade measurements even
though there is no audible noise.
6.6 Audio Input/ADC Tab
The Audio Input/ADC Tab is laid out like an audio mixing console. Each input channel has a vertical strip
that corresponds to that channel. LINE1L and LINE1R input strips have controls to route that input to
either the left or right ADC input; by default, all inputs are muted when the TLV320AIC32 is powered up.
To route an input to the ADC, first click on the MUTE button in the input channel strip which corresponds
to the ADC input channel you want that input to go to—the caption on the button will change to ACTIVE.
The level of the input channel routed to that particular ADC channel can then be adjusted using the Level
knob below the MUTE/ACTIVE button. See Figure 5 .
TLV320AIC32EVM and TLV320AIC32EVM-PDK User's Guide14 SBAU113 – November 2005
Figure 5. Audio Input Tab
www.ti.com
Similarly, the LINE2L and LINE2R inputs can be routed to the ADC. However, note that these inputs do
not have the choice to route to either ADC channel, they can only be configured to connect to the
corresponding ADC input.
The MIC3L and MIC3R inputs are similar to the LINE1L and LINE1R inputs in that they can be routed to
either ADC input channel. Control of the mic bias is accomplished by using the pull-down menu at the top
of these channel strips. The mic bias can either be powered down or set to 2.0V, 2.5V, or the power
supply voltage of the ADC (AVDD_ADC).
To use the on-board microphone, JMP3 and JMP4 must be installed and nothing should be plugged into
J8. In order for the mic bias settings in the software to take effect, JMP10 should be set to connect
positions 2 and 3, so that mic bias is controlled by the TLV320AIC32.
In the upper right of this tab are controls for Weak Common Mode Bias. Enabling these controls will
result in unselected inputs to the ADC channels to be weakly biased to the ADC common mode voltage.
Below these controls are the controls for the ADC PGA—the master volume controls for the ADC inputs.
Each channel of the ADC can be powered up or down as needed using the Powered Up buttons. PGA
soft-stepping for each channel is selected using the control below this. The large knobs set the actual
ADC PGA Gain; at the extreme counterclockwise rotation, the channel is muted. Rotating the knob
clockwise increases the PGA gain.
6.7 Audio Interface Tab
The Audio Interface tab (Figure 6 ) sets up the audio data interface to the TLV320AIC32. For use with the
PC software and the USB-MODEVM, the default settings should be used. If using an external I2S source,
or other data source, the interface mode may be selected using the Transfer Mode control—selecting
either I2S mode, DSP mode, or Right- or Left-Justified modes. Word length can be selected using the
Word Length control, and the bit clock rate can also be selected using the Bit Clock rate control. The
Data Word Offset, used in TDM mode (see the product datasheet ) can also be selected on this tab.
Kit Operation
SBAU113 – November 2005 TLV320AIC32EVM and TLV320AIC32EVM-PDK User's Guide 15
Loading...