Filter Wizard: simplify updating Tx PLL multiplier after DAC divider switch

We use the previously determined value for the Rx PLL multiplier instead
of recalculating.

Author: Tim Harder

AD9361_Filter_Wizard/AD9361_Filter_Wizard.m

@@ -192,10 +192,7 @@ function AD9361_Filter_Wizard_OpeningFcn(hObject, eventdata, handles, varargin)
     DAC_div = ADC_rate / DAC_rate;
     if ~(handles.input_tx.DAC_div == DAC_div)
         handles.input_tx.DAC_div = DAC_div;
-        handles.input_tx.PLL_mult = fastest_FIR([64 32 16 8 4 2 1], ...
-            handles.MAX_BBPLL_FREQ, handles.MIN_BBPLL_FREQ, ...
-            handles.input_tx.Rdata * handles.input_tx.FIR * handles.input_tx.HB1 * ...
-            handles.input_tx.HB2 * handles.input_tx.HB3 * handles.input_tx.DAC_div);
+        handles.input_tx.PLL_mult = handles.input_rx.PLL_mult;
         filter_type = get(handles.filter_type, 'Value');
         set(handles.filter_type, 'Value', 0);
         handles.input_tx.caldiv = default_caldiv(handles);

AD9361_Filter_Wizard/cook_input.m

@@ -205,6 +205,14 @@
 
 cooked = input;
 
+function rate = fastest_FIR(rates, max, min, mult)
+for i = 1:length(rates)
+    if max >= mult * rates(i) && min <= mult * rates(i)
+        break;
+    end
+end
+rate = rates(i);
+
 function caldiv = default_caldiv(input)
 if strcmp(input.RxTx, 'Rx')
     wnom = 1.4 * input.Fstop; % Rx