diff --git a/doc/xschem_man/tutorial_xschem_sky130.html b/doc/xschem_man/tutorial_xschem_sky130.html
index f78e9444..1d419c5c 100644
--- a/doc/xschem_man/tutorial_xschem_sky130.html
+++ b/doc/xschem_man/tutorial_xschem_sky130.html
@@ -23,7 +23,11 @@ p{padding: 15px  30px 10px;}
  </p>
  <ul>
   <li> Install Xschem. Follow the Manual <a href="install_xschem.html">Install instructions</a></li>
-
+  <p class="important">
+   If you install xschem from sources ensure no xschem package is already installed in your linux system. Packaged xschem versions
+   are too old so you should remove the installed package. The command for ubuntu/Debian systems is 
+  <kbd>sudo apt-get remove --purge xschem </kbd><br>
+  </p><br>
   <li> Install the Magic VLSI layout editor. Instructions <a href="http://opencircuitdesign.com/magic/index.html">here.</a></li>
 
   <li> Install <a href="https://sourceforge.net/projects/ngspice/">ngspice</a>, by cloning the git source repository
diff --git a/src/flatten.awk b/src/flatten.awk
index 339d4a89..de95a7a5 100755
--- a/src/flatten.awk
+++ b/src/flatten.awk
@@ -45,9 +45,12 @@ BEGIN{
  nodes["I"]=2; nodes["C"]=2; nodes["L"]=2; nodes["Q"]=3
  nodes["E"]=4; nodes["G"]=4; nodes["H"]=2; nodes["F"]=2
  nodes["B"]=2; nodes["S"]=4
+ controlblock = 0
 }
 {
- if( toupper($0) !~/^(\.INCLUDE|\.LIB|\.WRITE| *WRITE)/) $0=toupper($0)
+ if(toupper($0) ~ /^[ \t]*\.CONTROL/) controlblock = 1
+ if(controlblock == 0 && toupper($0) !~/^(\.INCLUDE|\.LIB|\.WRITE| *WRITE)/) $0=toupper($0)
+ if(toupper($0) ~ /^[ \t]*\.ENDC/) controlblock = 0
  # allow to specify *.nodes[W]=2 or *.nodes["W"] = 2 metadata in the netlist for additional
  # custom devices nodes specification.
  if($0 ~/^[ \t]*\*\.[ \t]*NODES\["?[^]["]"?\][ \t]*=[ \t]*.*/) {
@@ -76,6 +79,8 @@ BEGIN{
 } 
 
 END{
+
+ for(j=0;j<lines;j++) a[j] = trim_quoted_spaces(a[j])
  devpattern = "^["
  for(j in nodes) {
    devpattern = devpattern j
@@ -84,6 +89,7 @@ END{
  for(j=0;j<lines;j++) 
  {
   $0=a[j]
+
   if($1 ~ /\.GLOBAL/)			# get global nodes
    for(i=2;i<=NF;i++) global[$i]=i;
   if($1 ~ /^\.SUBCKT/)			# parse subckts
@@ -138,10 +144,14 @@ function expand(name, path, param,ports,   		# func. params
   paramarray2[parameter[1]]=parameter[2]
  }
  split(ports,portarray)
+ controlblock = 0
  for(j=subckt[name , "first"]+1;j<subckt[name , "last"];j++)
  {
+  if(a[j] ~ /^[ \t]*\.control/) controlblock = 1
   num=split(a[j],line)
-  if(line[1] ~ /^X/ )
+  if(controlblock) {
+    print a[j]
+  } else if(line[1] ~ /^X/ )
   {
    paramlist = ""; portlist = ""; subname=""
    for(k=num;k>=2;k--)
@@ -217,6 +227,7 @@ function expand(name, path, param,ports,   		# func. params
    }
    printf "\n"
   }
+  if(a[j] ~ /^[ \t]*\.endc/) controlblock = 0
  }
 }
 
@@ -284,4 +295,18 @@ function general_sub(string,name,pathnode,portarray,       nod, sss, state, last
  }
  sss=sss string
  return sss
-}                                      
+}
+
+function trim_quoted_spaces(s,                p, m)
+{
+  p = ""
+  while(match(s, /['{][^}']*['}]/)) {
+    m = substr(s, RSTART, RLENGTH)
+    gsub(/ /, "", m)
+    p = p substr(s, 1, RSTART -1) m
+    s = substr(s, RSTART + RLENGTH)
+  }
+  p = p s
+  return p
+}
+
diff --git a/xschem_library/examples/mos_power_ampli.sch b/xschem_library/examples/mos_power_ampli.sch
index 479c539b..b23b1d16 100644
--- a/xschem_library/examples/mos_power_ampli.sch
+++ b/xschem_library/examples/mos_power_ampli.sch
@@ -16,8 +16,8 @@ y1=-47
 y2=50
 divy=4
 subdivy=4
-x1=0.00824068
-x2=0.00893539
+x1=0.00823137
+x2=0.00892608
 divx=8
 subdivx=1
 dataset=0
@@ -34,8 +34,8 @@ y1=0
 y2=160
 divy=4
 subdivy=9
-x1=0.00824068
-x2=0.00893539
+x1=0.00823137
+x2=0.00892608
 divx=8
 subdivx=9
 dataset=0
@@ -52,8 +52,8 @@ y1=-0.19
 y2=160
 divy=4
 subdivy=9
-x1=0.00824068
-x2=0.00893539
+x1=0.00823137
+x2=0.00892608
 divx=8
 subdivx=9
 dataset=0
@@ -322,7 +322,7 @@ C {ngspice_get_expr.sym} 800 -1090 0 1 {name=r8
 node="[format %.4g [expr [ngspice::get_voltage e4] - [ngspice::get_voltage c7]]]"
 descr = veb
 }
-C {ngspice_get_expr.sym} 860 -1070 0 0 {name=r16 
+C {ngspice_get_expr.sym} 880 -1070 0 0 {name=r16 
 node="[format %.4g [expr [ngspice::get_current \{q4[ic]\}] / [ngspice::get_current \{q4[ib]\}] ] ]"
 descr = beta
 }
diff --git a/xschem_library/logic/testbench.sch b/xschem_library/logic/testbench.sch
index 7ab4c086..643b62eb 100644
--- a/xschem_library/logic/testbench.sch
+++ b/xschem_library/logic/testbench.sch
@@ -1,4 +1,5 @@
-v {xschem version=3.0.0 file_version=1.2 }
+v {xschem version=3.1.0 file_version=1.2
+}
 G {process
 begin
 A<='0';
@@ -217,7 +218,8 @@ C {use.sym} 40 -670 0 0 {------------------------------------------------
 library ieee;
         use ieee.std_logic_1164.all;
         use ieee.numeric_std.all;}
-C {ram.sym} 840 -630 0 0 {name=xcoderam   dim=5 width=8 hex=1 datafile=ram.list}
+C {ram.sym} 840 -630 0 0 {name=xcoderam   dim=5 width=8 hex=1 datafile=ram.list
+spice_ignore=true}
 C {lab_pin.sym} 990 -690 0 1 {name=p25 lab=DOUT[7:0]}
 C {lab_pin.sym} 690 -690 0 0 {name=p26 lab=ADD[4:0]}
 C {lab_pin.sym} 690 -650 0 0 {name=p27 lab=DIN[7:0]}
@@ -233,7 +235,7 @@ C {lab_pin.sym} 220 -220 0 1 {name=p37 lab=OEN verilog_type=reg}
 C {lab_pin.sym} 220 -200 0 1 {name=p38 lab=CK verilog_type=reg}
 C {lab_pin.sym} 220 -260 0 1 {name=p39 lab=CEN verilog_type=reg}
 C {lab_pin.sym} 220 -300 0 1 {name=p40 lab=M[7:0] verilog_type=reg}
-C {sync_reg.sym} 840 -810 0 0 {name=x8 width=8}
+C {sync_reg.sym} 840 -810 0 0 {name=x8 width=8 spice_ignore=true}
 C {lab_pin.sym} 740 -840 0 0 {name=p33 lab=DIN[7:0]}
 C {lab_pin.sym} 740 -780 0 0 {name=p41 lab=CK}
 C {lab_pin.sym} 740 -800 0 0 {name=p42 lab=BN}