Datasheet
Evaluation Board User Guide UG-045
Rev. 0 | Page 3 of 32
SETTING UP THE EVALUATION BOARD
STANDALONE MODE
It is possible to run the board and the AD1938 codec in stand-
alone mode, which fixes the functionality of the AD1938 into
the I
2
S data format, running at 256 × f
S
(default register con-
dition). The ADC BCLK and LRCLK ports are flipped between
slave and master (input and output) by tying SDA/COUT (Pin 24)
to low or high. This is accomplished by moving the J5 jumper to
either 0 or SDA/1 (see Figure 2 and Figure 3 for the correct
settings).
08421-002
0
SDA/1
COUT
0
1
CIN
J6 J8J7
ADDR1ADDR0
J5
0
SCL
CCL
K
0
1
CLATCH
Figure 2. Standalone Slave Mode
08421-003
0
SDA/1
COUT
0
1
CIN
J6 J8J7
ADDR1ADDR0
J5
0
SCL
CCL
K
0
1
CLATCH
Figure 3. Standalone Master Mode
With the control jumpers set to standalone slave mode, both
DIP switches, S2 and S3, set to off, and both rotary hex mode
switches, S4 and S5, set to 0, the S/PDIF receiver is the LRCLK,
BCLK, and SDATA source. The default MCLK jumper setting
routes MCLK from the S/PDIF receiver to the AD1938. With a
valid S/PDIF data stream connected to the selected S/PDIF
input port, the board passes audio from the S/PDIF port to all
four stereo outputs and from Stereo IN1 to the S/PDIF output
ports. IN2 can be selected by changing S3, Position 8, to on.
Other serial audio clock and data routing configurations are
described in the Switch and Jumper Settings section.
SPI CONTROL
The evaluation board can be configured for interactive control
of the registers in the AD1938 by connecting the SPI port to the
USBi. The SPI jumper settings are shown in Figure 4.
08421-004
0
SDA/1
COUT
0
1
CIN
J6 J8J7
ADDR1ADDR0
J5
0
SCL
CCL
K
0
1
CLATCH
Figure 4. SPI Control
The Automated Register Window Builder software controls
the AD1938 and is available at www.analog.com/AD1938.
AUTOMATED REGISTER WINDOW BUILDER
SOFTWARE INSTALLATION
The Automated Register Window Builder is a program that
launches a graphical user interface for direct, live control of the
AD1938 registers. The GUI content for the part is defined in a
part-specific .xml file; this file is included in the software
installation. To install the Automated Register Window
Builder software, follow these steps:
1. At www.analog.com/AD1938, find the Resources & Tools
list.
2. In the list, find Evaluation Boards & Development Kits
and click Evaluation Boards/Tools to open the provided
ARWBvXX.zip file.
3. Double-click the provided .msi file to extract the files to an
empty folder on your PC.
4. Then double-click setup.exe and follow the prompts to
install the Automated Register Window Builder. A
computer restart is not required.
5. Copy the .xml file for the AD1938 from the extraction
folder into the C:\Program Files\Analog Devices
Inc\AutomatedRegWin folder, if it does not appear in the
folder after installation.
HARDWARE SETUP, USBi
To set up the USBi hardware, follow these steps:
1. Plug the USBi ribbon cable into the J1 header.
2. Connect the USB cable to your computer and to the USBi.
3. When prompted for drivers, follow these steps:
a. Choose Install from a list or a specific location.
b. Choose Search for the best driver in these locations.
c. Check the box for Include this location in the search.
d. Find the USBi driver in C:\Program Files\Analog
Devices Inc\AutomatedRegWin\USB drivers.
e. Click Next.
f. If prompted to choose a driver, select CyUSB.sys.
g. If the PC is running Windows XP and you receive a
message that the software has not passed Windows
logo testing, click Continue Anyway.
You can now open the Automated Register Window Builder
application and load the .xml file for the part on the evaluation
board.
POWERING THE BOARD
The AD1938 evaluation board requires a power supply input of
±12 V dc and ground to the three binding posts; +12 V draws
~250 mA, and −12 V draws ~100mA. The on-board regulators
provide two 3.3 V rails, one each for AVDD and DVDD for the
AD1938. DVDD also supplies power for the active peripheral
components on the board. Jumpers are provided to allow access
to the power connections of the AD1938. These are convenient
points to insert a current measuring device. The only compon-
ents on the AD1938 side of the jumper are the part itself and the
local power supply decoupling. The jumper blocks on the
evaluation board are shown in Figure 5.