4410: add ram modulation with synchronization example

4410-4412.tex

@@ -518,6 +518,30 @@ The expected waveform is plotted on the following figure.
     \caption{Expected waveform from the RAM modulation example}
 \end{figure}
 
+Multiple RAM channels can also be synchronized.
+Similar to the 10 MHz single-tone RF signals, specify \texttt{phase} when calling \texttt{dds.set()} in \texttt{configure\char`_ram\char`_mode}.
+For example, set phase to 0 for the channels (\texttt{phase=0.0}).
+\begin{minted}{python}
+    dds.set(10*MHz, phase=0.0, profile=-1)
+\end{minted}
+Then, replace the \texttt{run()} function with the following.
+\begin{minted}{python}
+@kernel
+def run(self):
+    self.core.reset()
+    self.core.break_realtime()
+    self.cpld.init()
+
+    self.init_dds(self.dds0)
+    self.init_dds(self.dds1)
+    self.dds0.set_phase_mode(PHASE_MODE_TRACKING)
+    self.dds1.set_phase_mode(PHASE_MODE_TRACKING)
+
+    self.configure_ram_mode(self.dds0)
+    self.configure_ram_mode(self.dds1)
+\end{minted}
+Two phase-coherent RF signal with the same waveform as the previous figure should be generated.
+
 \newpage
 
 \section{Ordering Information}