User Guide
EVAL-ADMV8526
EVALUATION BOARD SOFTWARE
analog.com
Rev. 0 | 7 of 17
Table 1. ADMV8526 Chip Plug-In Label Functions (See
Figure 7
)
Label
Function
D
The displayed block diagram section shows the capacitor codes for the filter. While in
SPI Write
mode, any changes to the WR registers automatically triggers
a read operation of the
READBACK
registers, so that this section always reflects the actual hardware.
E
The
Filter Settings
section shows several controls for configuring the filter. Depending upon if
INTERPOLATE
is enabled, various controls can be visible.
When
INTERPOLATE
is enabled (as shown
Figure 7
), the following controls are visible:
FC_LOAD Value:
this numeric up and down box (0 to 255) is used to set the desired center frequency value. Note that this is a unitless quantity, where a 0
corresponds to the lowest center frequency, and 255 corresponds to the highest center frequency.
Requested FC:
enter in a requested center frequency in this text box. The value entered is used to compute the closest
FC_LOAD Value
for that frequency of
operation.
Anticipated FC:
this text box is an estimation of the operating center frequency based upon the
FC_LOAD Value
.
INTERPOLATE:
this check box enables the interpolation functionality on the chip.
When
INTERPOLATE
is disabled (not shown in
Figure 7
), the following controls are visible:
FC_LOAD Value:
this numeric up and down box (0 to 255) is used to set the desired center frequency capacitor code.
BW_LOAD Value:
this numeric up and down box (0 to 255) is used to set the desired bandwidth capacitor code.
MATCH_LOAD Value:
this numeric up and down box (0 to 255) is used to set the desired input and output match capacitor code.
INTERPOLATE:
this check box enables the interpolation functionality on the chip.
READBACK Values to Filter Settings:
this button is available when interpolation is disabled. Click this button to populate the read back values from the
hardware into the FC_LOAD, BW_LOAD, and MATCH_LOAD values.
F
The
Display
section determines the actively selected SPI write or LUT number. This section includes the following:
Mode:
use the drop-down menu to select either write or LUT display mode. When the display mode is set to write, then the
Filter Settings
section updates the
WR registers.
LUT:
when the
Mode
is set to
LUT
, scroll up and down to set the LUT number (0 to 31) that is currently being configured and displayed in the
Filter Settings
section. Changing to the LUT number automatically changes the
Mode
to
LUT
.
G
Use the
Logic Pins
section to toggle the SDP-S logic pins, which are connected to the logic pins on the
ADMV8526
chip. This section includes the following:
RSTB:
clear the check box to bring the ADMV8526 RST pin low, which holds the chip in reset. Select the check box again to bring the chip out of reset.
SFL:
select the check box to bring the ADMV8526 SFL pin high, which places the chip in SFL mode. This action also toggles the on-board
ADG749BKSZ
switch connected to the ADMV8526 CS pin (see
Figure 12
). While in SFL mode, the ADMV8526 CS pin is connected to the SDP-S logic pin, CSB_AUX, and
normal SPI transactions are disallowed.
CSB_AUX:
this pin is only available in SFL mode. Selecting the check box brings the CSB_AUX pin high, which advances the internal state machine pointer
to the next LUT. If an external waveform generator is connected to the CSB_EXT port on the ADMV8526-EVALZ, the CSB_AUX pin has no effect, and the
CSB_EXT port takes precedence.
H
Click
Proceed to Memory Map
to open the
ADMV8526 Memory Map
(see
Figure 8
)
J1
All changes, except those made within the
CONFIGURATION
section, do not take effect until clicking
Apply Changes.
If
Auto Apply
is highlighted in the
ADMV8526 Board
tab (see
Figure 5
), the
Apply Changes
feature continuously runs every few seconds, and users do not have to click the
Apply Changes
to
apply or read back the block diagram settings.
J2
To read back all of the SPI registers of the chip, click
Read All
.
J3
Click
Reset Chip
to reset the chip.
J4
Click
Diff
to show registers that are different on the chip.
J5
Click
Software Defaults
to restore the software defaults to the chip, and then click
Apply Changes
. The software defaults for the ADMV8526 registers are
zero, except for Register 0x011, which is set to 0x7F, and the interpolation coefficients in Register 0x300 to Register 0x30F.
J6
Click
Memory Map Side-By-Side
to enable the side by side memory map view.
K
Click
Interpolation Coefficients
to open the subdiagram for displaying and editing the interpolation coefficients (see
Figure 9
). The interpolation coefficients
can be changed to calibrate the center frequency and/or change the desired operating bandwidth of the filter. Once the
Interpolation Coefficients
subdiagram
is visible, an additional button,
Calibration
, is available. Click
Calibration
to open the additional subdiagram (see
Figure 10
) for performing the recommended
calibration sequence. Refer to the ADMV8526 data sheet theory of operations section for guidance on editing the interpolation coefficients.
