RadioProcessor
DDS (Frequency and Phase) Registers
The RadioProcessor contains three DDS channels, two of which are internal and used for digital detection
(cos and sin), and one which drives the digital-to-analog converter (DAC) that forms the TX channel (see
Figure 8 next page). The frequency and phases of these three channels are controlled by selecting values
from a bank of on-board registers. These registers are typically programmed during board initialization, and
then the pulse program is used to select which register is used at any given time during an experiment. All
three channels share a common frequency, but their phase may be set completely independent of each other.
The number of available registers for each channel is given in the table below
(1)
Register Bank
Number of registers
Frequency
16
Cos phase (real channel)
4
Sin phase (imaginary channel)
4
TX phase
16
Table 2:
DDS Register information
(1)
.
Relevant spinapi functions:
pb_start_programming()
pb_set_phase()
pb_set_freq()
pb_stop_programming()
Firmware revision 10-18 supports “on the fly” frequency and phase register programming. Please see
Appendix V for more information.
(1) Certain RadioProcessor firmware revisions have different register allocation. For information about a specific RadioProcessor
firmware revision see Appendix VII or contact SpinCore Technologies, Inc. Custom designs with more DDS registers are available.
2020-10-07
17
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