example update: sim_status, mc_source and others

examples/Monte_Carlo/MC_2_control.sp

@@ -1,3 +1,4 @@
+*ng_script
 * Perform Monte Carlo simulation in ngspice
 * script for use with 25 stage Ring-Osc. BSIM3
 * circuit is in MC_2_circ.sp
@@ -5,9 +6,8 @@
 * start script by 'ngspice -o MC_2_control.log MC_2_control.sp'
 *
 .control
-  save buf                     $ we just need output vector buf, save memory by more than 10x
-  let mc_runs = 10             $ number of runs for monte carlo
-  let run = 1                  $ number of the actual run
+  let mc_runs = 10                $ number of runs for monte carlo
+  let run = 1                     $ number of the actual run
 
 * Where to find the circuit netlist file MC_2_circ.sp
   set sourcepath = ( D:\Spice_general\ngspice\examples\Monte_Carlo )
@@ -19,14 +19,14 @@
   dowhile run <= mc_runs
     * without the reset switch there is some strange drift
     * towards lower and lower frequencies
-    reset
-    set run ="$&run"              $ create a variable from the vector
-    set rndseed = $run            $ set the rnd seed value to the loop index
+    set run = $&run               $ create a variable from the vector
+    setseed $run                  $ set the rnd seed value to the loop index
     if run = 1
        source MC_2_circ.sp        $ load the circuit once from file, including model data
     else
        mc_source                  $ re-load the circuit from internal storage
     end
+    save buf                      $ we just need output vector buf, save memory by more than 10x
     tran 15p 200n 0
     write mc_ring{$run}.out buf   $ write each sim output to its own rawfile
     linearize buf                 $ lienarize buf to allow fft

examples/Monte_Carlo/MC_ring.sp

@@ -1,5 +1,9 @@
 Perform Monte Carlo simulation in ngspice
-* 25 stage Ring-Osc. BSIM3
+* 25 stage Ring-Osc. BSIM3 with statistical variation of various model parameters
+* cd into ngspice/examples/Monte_Carlo
+* start in interactive mode 'ngspice MC_ring.sp' with several plots for output
+* or start in batch mode, controlled by .control section (Control mode)
+* with 'ngspice -b -r MC_ring.raw -o MC_ring.log MC_ring.sp'.
 
 vin in out dc 0.5 pulse 0.5 0 0.1n 5n 1 1 1
 vdd dd 0 dc 3.3
@@ -151,6 +155,15 @@ cout  buf ss 0.2pF
     reset
   end
 ***** plotting **********************************************************
+if $?batchmode
+  echo
+  echo Plotting not available in batch mode
+  echo Write linearized vout0 to vout{$mc_runs} to rawfile $rawfile
+  echo
+  write $rawfile {$plot_out}.allv
+  rusage
+  quit
+else
   setplot $plot_out
   plot vout0  ylabel 'RO output, original parameters'        $ just plot the tran output with nominal parameters
   setplot $plot_fft
@@ -171,7 +184,7 @@ cout  buf ss 0.2pF
   * put data into the correct bins
   let run = 0
   dowhile run < mc_runs
-    set run = "$&run"             $ create a variable from the vector
+    set run = $&run               $ create a variable from the vector
     let val = maxffts[{$run}]
     let part = 0
     * Check if val fits into a bin. If yes, raise bin by 1
@@ -199,6 +212,7 @@ cout  buf ss 0.2pF
   let diff40 = (vecmax(halfffts) - vecmin(halfffts))*1e-6
   echo
   echo Max. jitter is "$&diff40" MHz
+end   
   rusage
 .endc
 ********************************************************************************