UG-207 Datasheet, PDF (14/16 Pages) Analog Devices – Evaluation Board for 1 GSPS DDS with 14-Bit DAC

UG-207
RAM OPERATION
Evaluation Board User Guide
Figure 13. Profiles Window When Using the RAM
Use of RAM on the AD9910 should not be attempted without
using the AD9910 data sheet as a reference. The AD9910 data
sheet contains detailed information on RAM operation. To use
the RAM on the AD9910, select the Enable RAM check box
on the Profiles window. This changes the appearance of the
window from single-tone mode to RAM control mode.
Each RAM Segment section corresponds to a different profile.
RAM Segment 0 corresponds to Profile 0. Use the Beginning
Address and Final Address text boxes to set the beginning and
ending addresses for the RAM sweep. The Address Step Rate
sets the 16-bit address step rate value. The Mode Control drop-
down box sets the 3-bit RAM control word mode. See the
AD9910 data sheet for a complete description of the RAM
operating modes. The Zero Crossing check box sets the zero-
crossing bit. This bit is effective only in RAM mode using direct
switch. The No Dwell check box sets the no-dwell high bit. This
bit is only effective when the RAM mode is in ramp-up.
Use the Activate area to switch between profiles. Use the
Internal Profile Control drop-down box to select the internal
profile control configurations. Refer to the AD9910 data sheet
for detailed information on the RAM internal profile control
modes. Use the RAM Data Type drop-down box to select the
RAM playback destination. Refer to the AD9910 data sheet for
further details on the RAM playback destination bits.
Use the LOAD button to display the RAM I/O window.
RAM I/O
Figure 14. RAM I/O Window
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