Re-make pll-xspice.cir as a wrapper around shared-pll-xspice.cir,

behaviour as before.  Add similar pll-digital-iplot.cir as a
demonstration of iplot with analogue and digital nodes.

examples/xspice/pll/pll-digital-iplot.cir

@@ -0,0 +1,20 @@
+* pll circuit using xspice code models: version with iplot including
+* digital nodes.
+
+.include shared-pll-xspice.cir
+
+* An additional node to scale the analog signal.
+
+bdisplay controlX4 0 v=v(cont)*4
+
+.control
+save cont controlX4 s1 s2 u1n d1 v.xlf.vdd#branch; to save memory
+iplot -o controlx4 d_d+4.5 d_u
+tran 0.1n $&simtime uic
+rusage
+plot cont s1 s2+1.2 u1n+2.4 d1+3.6 xlimit 4u 5u
+plot v.xlf.vdd#branch xlimit 4u 5u ylimit -8m 2m
+*plot cont
+.endc
+
+.end

examples/xspice/pll/pll-xspice.cir

@@ -0,0 +1,15 @@
+* pll circuit using xspice code models: version with analog-only iplot
+* output frequency 400 MHz
+* locked to a 1 or 10 MHz reference
+
+.include shared-pll-xspice.cir
+
+.control
+save cont s1 s2 u1n d1 v.xlf.vdd#branch; to save memory
+iplot -d 4000 cont
+tran 0.1n $&simtime uic
+rusage
+plot cont s1 s2+1.2 u1n+2.4 d1+3.6 xlimit 4u 5u
+plot v.xlf.vdd#branch xlimit 4u 5u ylimit -8m 2m
+.endc
+.end

examples/xspice/pll/shared-pll-xspice.cir

@@ -1,4 +1,5 @@
-* pll circuit using xspice code models
+* pll circuit using xspice code models: shared by pll_xspice.cir and
+* pll_digital_iplot.cir
 * output frequency 400 MHz
 * locked to a 1 or 10 MHz reference
 
@@ -62,16 +63,6 @@ abridge-w1 [d_divout d_ref d_Un d_D] [s1 s2 u1n d1] dac1 ; change to d_u or d_Un
 + input_load = 5.0e-12 t_rise = 1e-10
 + t_fall = 1e-10)
 
-.control
-save cont s1 s2 u1n d1 v.xlf.vdd#branch; to save memory
-iplot -d 4000 cont
-tran 0.1n $&simtime uic
-rusage
-plot cont s1 s2+1.2 u1n+2.4 d1+3.6 xlimit 4u 5u
-plot v.xlf.vdd#branch xlimit 4u 5u ylimit -8m 2m
-*plot cont
-.endc
-
 *model = bsim3v3
 *Berkeley Spice Compatibility 
 * Lmin= .35 Lmax= 20 Wmin= .6 Wmax= 20
@@ -140,5 +131,3 @@ plot v.xlf.vdd#branch xlimit 4u 5u ylimit -8m 2m
 +Ua1= 4.312e-9 Ub1= 6.65e-19  Uc1= 0 
 +Kt1l=0
 
-
-.end