diff --git a/alliance/src/nero/src/AAstar.cpp b/alliance/src/nero/src/AAstar.cpp
index d70819a5..ab5b801c 100644
--- a/alliance/src/nero/src/AAstar.cpp
+++ b/alliance/src/nero/src/AAstar.cpp
@@ -1,7 +1,7 @@
 
 // -*- C++ -*-
 //
-// $Id: AAstar.cpp,v 1.5 2002/10/24 07:51:33 hcl Exp $
+// $Id: AAstar.cpp,v 1.6 2002/10/29 18:46:03 jpc Exp $
 //
 //  /----------------------------------------------------------------\ 
 //  |                                                                |
@@ -85,12 +85,13 @@ CAStar::CNodeASSet::~CNodeASSet (void)
 //
 // Check all allocated CNodeAS objects.
 
-void  CAStar::CNodeASSet::check (void)
+void  CAStar::CNodeASSet::check (bool cleared)
 {
   int  chunk, index, maxindex;
 
 
-  //cdebug << "+ Check all CNodeAS (" << _maxalloc << ")\n";
+  cerr << "+   Check all CNodeAS ( used := " << _maxused
+       << ", allocated := " << _maxalloc << endl;
 
   for (chunk = 0; chunk < _maxchunk; chunk++) {
     if (chunk > _maxalloc / D::CHUNK_SIZE) {
@@ -104,11 +105,13 @@ void  CAStar::CNodeASSet::check (void)
 
     for (index = 0; index < maxindex; index++) {
       if ( _chunks[chunk][index].point.inside() ) {
-        //cdebug << "+ Not reset CNodeAS found (id := "
-        //     << _chunks[chunk][index].id
-        //     << " (point := " << ")"
-        //     << _chunks[chunk][index].point
-        //     << endl;
+        if (cleared) {
+          cerr << "+     Not reset CNodeAS found (id := "
+               << _chunks[chunk][index].id
+               << " " << (void*)&(_chunks[chunk][index])
+               << " (point := " << _chunks[chunk][index].point << ")"
+               << endl;
+        }
       }
     }
   }
@@ -124,41 +127,22 @@ void  CAStar::CNodeASSet::check (void)
 
 void  CAStar::CNodeASSet::reset (void)
 {
-  int  chunk, maxchunk, index, maxindex, maxused_div, maxused_mod;
-
-
-  //cdebug << "+ CAStar::CNodeAS::resetall()." << endl;
-  //cdebug << "+   _maxused  := " << _maxused << endl;
-  //cdebug << "+   _maxalloc := " << _maxalloc << endl;
-  //cdebug << "+   _maxchunk := " << _maxchunk << endl;
+  int  chunk, index, maxindex, maxused_div, maxused_mod;
 
 
   if (_maxused > 0) {
     maxused_div = (_maxused - 1) / D::CHUNK_SIZE;
     maxused_mod = (_maxused - 1) % D::CHUNK_SIZE;
 
-    maxchunk = maxused_div + ( (maxused_mod) ? 1 : 0 );
-  } else {
-    maxchunk = 0;
-  }
+    for (chunk = 0; chunk <= maxused_div; chunk++) {
+      maxindex = D::CHUNK_SIZE - 1;
 
-  for (chunk = 0; chunk < maxchunk; chunk++) {
-    maxindex = D::CHUNK_SIZE - 1;
+      // Incomplete last chunk.
+      if (chunk == maxused_div) maxindex = maxused_mod;
 
-    // Incomplete last chunk.
-    if ( (chunk == maxchunk - 1) && (maxused_mod != 0) )
-      maxindex = maxused_mod;
-
-    //cdebug << "+   Index range := [" << chunk * D::CHUNK_SIZE
-    //     << "," <<  chunk * D::CHUNK_SIZE + maxindex << "]"
-    //     << " (chunk := " << chunk << ", maxindex := " << maxindex << ")"
-    //     << endl;
-
-    for (index = 0; index <= maxindex; index++) {
-      //cdebug << "+     index := " << index
-      //     << " (" << &_chunks[chunk][index] << ")"
-      //     << endl;
-      _chunks[chunk][index].reset ();
+      for (index = 0; index <= maxindex; index++) {
+        _chunks[chunk][index].reset ();
+      }
     }
   }
 
@@ -232,9 +216,9 @@ void *CAStar::CNodeAS::operator new (size_t size, CNodeASSet &NS)
     // Use a new element.
     NS._maxused++;
 
-  } while (!new_chunk                        &&
-           (NS._maxused <= NS._maxalloc) &&
-           NS._chunks[chunk][index].intree );
+  } while (    !new_chunk
+           && (NS._maxused <= NS._maxalloc)
+           &&  NS._chunks[chunk][index].intree );
 
   NS._maxalloc = max (NS._maxalloc, NS._maxused);
   NS._chunks[chunk][index].id = NS._maxused - 1;
@@ -257,24 +241,12 @@ void CAStar::CNodeAS::reset (void)
   queued   = false;
   tagged   = false;
 
-  //CDRGrid::iterator  old_point;
 
   if ( !intree ) {
     if ( point.inside() ) {
-      //cdebug << "+   reset CNodeAS (" << this
-      //     << ") id := " << id << ", point " << point
-      //     << " (node := " << &point.node() << ")"
-      //     << endl;
-      //old_point = point;
       point.node().algo = NULL;
       point.unlink ();
-
-      //old_point.node().check ();
-    //} else {
-    // cdebug << "+   reset CNodeAS id := " << id << " has point outside!." << endl;
     }
-  //} else {
-  //  cdebug << "+   reset CNodeAS id := " << id << " is in tree." << endl;
   }
 }
 
@@ -287,11 +259,13 @@ void CAStar::CNodeAS::reset (void)
 void  CAStar::CNodeAS::successors (CNodeASSet &NS, CNet *net, CNodeAS *(*success)[6])
 {
   CDRGrid::iterator  neighbor;
+  CDRGrid::iterator  neighbor2;
                CNet *pNet;
             CNodeAS *pNodeAS;
 
-  int   cost_x, cost_y, cost_z, cost, edge;
+  int   cost_x, cost_y, cost_z, cost, edge, i, j;
   long  new_distance, new_remains;
+  bool  skip;
 
 
 
@@ -311,7 +285,18 @@ void  CAStar::CNodeAS::successors (CNodeASSet &NS, CNet *net, CNodeAS *(*success
     cost_y = D::cost_ALU3_Y;
   }
 
+  for (edge = 0; edge < 6; edge++) (*success)[edge] = NULL;
+
   for (edge = 0; edge < 6; edge++) {
+    cdebug << "+     successors[] : (before edge " << edge << ")\n";
+    for (j = 0; j < 6; j++) {
+      cdebug << "+       " << (void*)(*success)[j];
+      if ((*success)[j] != NULL)
+        cdebug << " " << (*success)[j]->point << "\n";
+      else
+        cdebug << "\n";
+    }
+
     neighbor = point;
     switch (edge) {
       case 0: cost = cost_x; neighbor.left();   break; 
@@ -328,8 +313,8 @@ void  CAStar::CNodeAS::successors (CNodeASSet &NS, CNet *net, CNodeAS *(*success
 
       pNodeAS = AS (neighbor);
       if (!pNodeAS) {
-        //cdebug << "+     new CNodeAS." << endl;
         pNodeAS = new (NS) CNodeAS (neighbor);
+        cdebug << "+     new CNodeAS " << (void*)pNodeAS << "\n";
       }
 
       // Check if the node is an obstacle.
@@ -341,6 +326,39 @@ void  CAStar::CNodeAS::successors (CNodeASSet &NS, CNet *net, CNodeAS *(*success
       if (neighbor.z()) {
         // Check if the current net can take the node.
         if (!neighbor.take (neighbor.node().data.pri)) continue;
+
+        // For the junction layer, allow up neighbor (i.e. VIAs)
+        // only on the 2 pitch grid.
+        if (   ((neighbor.z() == neighbor.zupper()    ) && (edge == 5))
+            || ((neighbor.z() == neighbor.zupper() - 1) && (edge == 4)) ) {
+          if (neighbor.zupper() % 2) {
+            if (neighbor.x() % 2) continue;
+          } else {
+            if (neighbor.y() % 2) continue;
+          }
+        }
+
+        if (neighbor.z() >= neighbor.zupper ()) {
+          skip = false;
+
+          for (i = 0; i < 2; i++) {
+            neighbor2 = neighbor;
+
+            switch (i) {
+              case 0: neighbor2.pprev (); break;
+              case 1: neighbor2.pnext (); break;
+            }
+
+            if (neighbor2.inside()) {
+              if (    neighbor2.node().data.obstacle
+                  || !neighbor2.take (neighbor2.node().data.pri) ) {
+                skip = true; break;
+              }
+            }
+          }
+
+          if (skip) continue;
+        }
       }
 
       // Case of locked nodes : belongs to global nets, never use it.
@@ -375,7 +393,9 @@ void  CAStar::CNodeAS::successors (CNodeASSet &NS, CNet *net, CNodeAS *(*success
         // Tag the node here : prevent double write in queue.
         if (!D::optim_AStar_queue) pNodeAS->tagged = true;
 
-        //cdebug << "+     Added to successor list." << endl;
+        cdebug << "+     Added to successor list [" << edge << "]\n";
+        cdebug << "+       " << (void*)pNodeAS << " " << neighbor << "\n";
+        cdebug << "+       " << (void*)pNodeAS << " " << pNodeAS->point << "\n";
         (*success)[edge] = pNodeAS;
       }
     }
@@ -405,6 +425,12 @@ void CAStar::CTree::addterm (CTerm &term)
     addnode (pNodeAS);
     pNodeAS->reset();
 
+    if (pNodeAS->point.outside ()) {
+      cerr << "+ TERMINAL NODE OUTSIDE : "
+           << (void*)pNodeAS
+           << " " << *itNode
+           << endl;
+    }
   }
 
   //cdebug << "+   Done." << endl;
@@ -575,12 +601,18 @@ bool  CAStar::step (void) throw (trapped_astar)
   for (edge = 0; edge < 6; edge++) {
     if (successors[edge] == NULL) continue;
 
-    cdebug << "+     " << successors[edge]->point << "\n";
+    cdebug << "+     " << "[" << edge << "] "
+           << (void*)successors[edge] << " "
+           << successors[edge]->point << "\n";
     // The successor belongs to the current net.
     // (it may be not the actual target).
     if (   (successors[edge]->point.node().data.owner == net)
         && (_tree.reached.find (successors[edge]->point.node().getid())
             == _tree.reached.end())) {
+      //cerr << "    Reached target := \""
+      //     << net->terms[successors[edge]->point.node().getid()]->name
+      //     << " (index := " << successors[edge]->point.node().getid() << ")"
+      //     << endl;
       _reached = successors[edge];
       return (false);
     }
@@ -611,8 +643,6 @@ bool  CAStar::nexttarget (void)
 
   // Reset all the nodeAS objects.
   _NS.reset ();
-
-  //CNodeAS::checkall ();
   //net->_drgrid->nodes->check ();
 
   // Select the next target.
@@ -622,7 +652,8 @@ bool  CAStar::nexttarget (void)
       _tree.settarget ( net->terms[i]->lowest() );
       //cerr << "    Next target := \""
       //     << net->terms[i]->name
-      //     << "\"\n";
+      //     << " (index := " << i << ")"
+      //     << endl;
       break;
     }
   }
@@ -643,8 +674,10 @@ bool  CAStar::nexttarget (void)
 
 void CAStar::backtrack (void)
 {
-  CNodeAS *node, *node_prev;
-  CNet    *del_net;
+  CDRGrid::iterator  neighbor;
+            CNodeAS *node, *node_prev;
+               CNet *del_net;
+                int  i;
 
 
   //cdebug << "+   Backtracking." << endl;
@@ -659,6 +692,23 @@ void CAStar::backtrack (void)
       _netsched->queue (del_net);
     }
 
+    if (node->point.z() >= node->point.zupper()) {
+      for (i = 0; i < 2; i++) {
+        neighbor = node->point;
+
+        switch (i) {
+          case 0: neighbor.pnext(); break;
+          case 1: neighbor.pprev(); break;
+        }
+
+        if (neighbor.inside() && (neighbor.node().data.pri > 0)) {
+          del_net = neighbor.node().data.owner;
+          del_net->unroute ();
+          _netsched->queue (del_net);
+        }
+      }
+    }
+
     _tree.addnode (node);
 
     node_prev = node;
@@ -694,10 +744,9 @@ bool CAStar::search (void)
       for (; step(); );
   
       backtrack ();
-    }
 
-    //CNodeAS::checkall ();
-    //net->_drgrid->nodes->check ();
+      //check (false);
+    }
 
     return (false);
   }
@@ -706,8 +755,7 @@ bool CAStar::search (void)
     abort ();
     cmess2 << "              > AStar unable to found a path.\n";
 
-    //CNodeAS::checkall ();
-    //net->_drgrid->nodes->check ();
+    //check (false);
   }
 
   return (true);
@@ -768,13 +816,11 @@ void CAStar::dump (void)
   iterations_reroute = 0;
   iterations_kind    = &iterations_route;
 
-  //if (pNet->name == "acc_i_down") cdebug.on ();
+  //if (pNet->name == "ram_banc1_nadr2x") cdebug.on ();
 
   do {
     if (hysteresis) {
-      cdebug << "About to clear." << "\n";
       clear ();
-      cdebug << "cleared." << "\n";
 
       pri = 255 + (1 << increase++);
 
@@ -785,18 +831,12 @@ void CAStar::dump (void)
     else
       pri = 0;
 
-    cdebug << "About to load net " << iterations_kind << "\n";
     load  (pNet, pri, expand);
-    cdebug << "loading done " << iterations_kind << "\n";
 
-    cdebug << "About to route net " << iterations_kind << "\n";
     routed = !search ();
-    cdebug << "routing done " << iterations_kind << "\n";
     *iterations_kind += iterations;
-    cdebug << "mark 1.\n";
 
     hysteresis = true;
-    cdebug << "mark 2.\n";
   } while ((increase < 15) && !routed);
 
   if (increase >= 15) throw reach_max_pri (pNet);
@@ -805,10 +845,9 @@ void CAStar::dump (void)
 
   clear ();
 
-  //CNodeAS::checkall ();
-  //pNet->_drgrid->nodes->check ();
+  //check (true);
 
-  //if (pNet->name == "ctl.seq_ep_30") exit (0);
+  //if (pNet->name == "cal_q_alu 0") { emergency (); exit (1); }
 }
 
 
@@ -817,20 +856,20 @@ void CAStar::dump (void)
 // -------------------------------------------------------------------
 // Method  :  "CMatrixNodes::check()".
 
-void  CMatrixNodes::check (void)
+void  CMatrixNodes::check (bool cleared)
 {
   int      index;
 
 
-  cdebug << "+ Check routing DB.\n";
+  cerr << "+   Check Nodes Matrix.\n";
   for (index = 0; index < _drgrid->XYZ; index++) {
     if ( &(*this)[index] == &hole ) continue;
 
-    if ( ! (*this)[index].check() )
-      cdebug << " (point := (" << _drgrid->x(index)
+    if (! (*this)[index].check(cleared))
+      cerr << "+     Grid point := (" << _drgrid->x(index)
            << "," << _drgrid->y(index)
-           << "," << _drgrid->z(index) << "))\n";
-                                      
+           << "," << _drgrid->z(index) << "))"
+           << endl;
   }
 }
 
@@ -840,23 +879,40 @@ void  CMatrixNodes::check (void)
 // -------------------------------------------------------------------
 // Method  :  "CNode::check()".
 
-bool  CNode::check (void)
+bool  CNode::check (bool cleared)
 {
   CAStar::CNodeAS *nodeAS;
 
 
   if ( algo != NULL ) {
-    cdebug << "+ Residual algo structure found!\n";
+    if (cleared)
+      cerr << "+   Residual algo structure found !" << endl;
 
     nodeAS = (CAStar::CNodeAS*) algo; 
 
     if ( nodeAS->point.outside() ) {
-      cdebug << "+ Incoherent algo structure found (node := "
+      cerr << "+     Incoherent algo structure found (node := "
            << this << ") : "
-           << nodeAS << " (id := " << nodeAS->id << ")";
+           << nodeAS << " (id := " << nodeAS->id << ")"
+           << endl;
+
       return ( false );
     }
   }
 
   return ( true );
 }
+
+
+
+
+// -------------------------------------------------------------------
+// Method  :  "CAStar::check()".
+
+void  CAStar::check (bool cleared)
+{
+  cerr << "+ Check routing DB.\n";
+
+  _drgrid->nodes->check (cleared);
+  _NS.check (cleared);
+}
diff --git a/alliance/src/nero/src/ADefs.h b/alliance/src/nero/src/ADefs.h
index d865d318..0cea111b 100644
--- a/alliance/src/nero/src/ADefs.h
+++ b/alliance/src/nero/src/ADefs.h
@@ -1,7 +1,7 @@
 
 // -*- C++ -*-
 //
-// $Id: ADefs.h,v 1.2 2002/10/13 14:22:47 jpc Exp $
+// $Id: ADefs.h,v 1.3 2002/10/29 18:46:03 jpc Exp $
 //
 // /-----------------------------------------------------------------\ 
 // |                                                                 |
@@ -177,7 +177,7 @@
 
       // Modifiers.
       public: void  reset (void);
-      public: void  check (void);
+      public: void  check (bool cleared);
 
       // Friend class (for CNodeAS allocator).
       friend class CNodeAS;
@@ -285,6 +285,9 @@
     public:  bool  search     (void);
     public:  void  route      (CNet *pNet) throw (reach_max_pri);
 
+
+    // Database integrity check.
+    public:  void  check (bool cleared);
   };
 
 
diff --git a/alliance/src/nero/src/MDRGrid.cpp b/alliance/src/nero/src/MDRGrid.cpp
index 79664022..6d60c85f 100644
--- a/alliance/src/nero/src/MDRGrid.cpp
+++ b/alliance/src/nero/src/MDRGrid.cpp
@@ -1,7 +1,7 @@
 
 // -*- C++ -*-
 //
-// $Id: MDRGrid.cpp,v 1.2 2002/10/17 21:57:27 jpc Exp $
+// $Id: MDRGrid.cpp,v 1.3 2002/10/29 18:46:03 jpc Exp $
 //
 //  /----------------------------------------------------------------\ 
 //  |                                                                |
@@ -324,17 +324,20 @@ int  CDRGrid::iterator::manhattan (iterator &other)
 // -------------------------------------------------------------------
 // Constructor  :  "CDRGrid::CDRGrid()".
 
-CDRGrid::CDRGrid (int x, int y, int z)
+  CDRGrid::CDRGrid (int x, int y, int z, int zup) throw (e_zupper)
 {
   int    index;
 
 
-  X    = x;
-  Y    = y;
-  Z    = z;
-  XY   = X  * Y;
-  XYZ  = XY * Z;
-  size = XY * (Z - 1);
+  X      = x;
+  Y      = y;
+  Z      = z;
+  XY     = X  * Y;
+  XYZ    = XY * Z;
+  size   = XY * (Z - 1);
+  zupper = zup;
+
+  if (zupper < 4) throw e_zupper (zupper);
 
 
   nodes = new CMatrixNodes (this);
diff --git a/alliance/src/nero/src/MDefs.h b/alliance/src/nero/src/MDefs.h
index 54f6ae91..3b03aeb9 100644
--- a/alliance/src/nero/src/MDefs.h
+++ b/alliance/src/nero/src/MDefs.h
@@ -1,7 +1,7 @@
 
 // -*- C++ -*-
 //
-// $Id: MDefs.h,v 1.3 2002/10/17 21:57:27 jpc Exp $
+// $Id: MDefs.h,v 1.4 2002/10/29 18:46:03 jpc Exp $
 //
 // /-----------------------------------------------------------------\ 
 // |                                                                 |
@@ -142,6 +142,27 @@
   };
 
 
+  // ---------------------------------------------------------------
+  // Too small zupper exception.
+
+  class e_zupper : public except_done {
+
+    // Attributes.
+    public: int  zupper;
+
+    // Constructor.
+    public: e_zupper (int  zup) { zupper = zup; }
+
+    // Destructor.
+    public: ~e_zupper (void) throw () { };
+
+    // Overridables.
+    public: const char* what () const throw () {
+              return ((char*)"\"zupper\" must not be lower than 4.");
+            }
+  };
+
+
 
 
   // ---------------------------------------------------------------
@@ -230,13 +251,22 @@
 
       public: friend ostream &operator<< (ostream &o, iterator &self);
 
-      public: void   valid   (bool validindex) throw (e_matrix_iterator);
-      public: int    x       (void) { return ( _drgrid->x (_index) ); }
-      public: int    y       (void) { return ( _drgrid->y (_index) ); }
-      public: int    z       (void) { return ( _drgrid->z (_index) ); }
-      public: bool   outside (void) { return ( _index == INT_MAX ); }
-      public: bool   inside  (void) { return ( !outside() ); }
-      public: int    manhattan (iterator &other) throw (e_matrix_iterator);
+      public: void  valid     (bool validindex) throw (e_matrix_iterator);
+      public:  int  x         (void) { return ( _drgrid->x (_index) ); }
+      public:  int  y         (void) { return ( _drgrid->y (_index) ); }
+      public:  int  z         (void) { return ( _drgrid->z (_index) ); }
+      public: bool  outside   (void) { return ( _index == INT_MAX ); }
+      public: bool  inside    (void) { return ( !outside() ); }
+      public: bool  onAB      (void) { if (   (x() == 0)
+                                           || (x() == _drgrid->X - 1) 
+                                           || (y() == _drgrid->Y - 1) 
+                                           || (y() == 0)) 
+                                         return (true);
+
+                                        return (false);
+                                     };
+      public:  int  manhattan (iterator &other) throw (e_matrix_iterator);
+      public:  int  zupper    (void) { return ( _drgrid->zupper ); }
 
       // Modifiers.
       public: void      unlink (void)
@@ -253,6 +283,14 @@
       public: iterator &up     (void) { return ( dy(+1) ); };
       public: iterator &bottom (void) { return ( dz(-1) ); };
       public: iterator &top    (void) { return ( dz(+1) ); };
+      public: iterator &pnext  (void) { if (z() % 2)
+                                          return ( right() );
+                                        return ( up() );
+                                      };
+      public: iterator &pprev  (void) { if (z() % 2)
+                                          return ( left() );
+                                        return ( down() );
+                                      };
 
     };
 
@@ -266,6 +304,7 @@
     public: int XY;
     public: int XYZ;
     public: int size;
+    public: int zupper;
     public: int cost_x_hor;
     public: int cost_x_ver;
     public: int cost_y_hor;
@@ -277,7 +316,7 @@
     public: CMatrixNodes *nodes;
 
     // Constructor.
-    public: CDRGrid  (int x, int y, int z);
+    public: CDRGrid  (int x, int y, int z, int zup) throw (e_zupper);
 
     // Destructor.
     public: ~CDRGrid (void);
@@ -402,7 +441,7 @@
     public: inline int  getid    (void) { return (data.ident - 1); }
     public: inline bool terminal (void) { return (data.ident != 0); }
     public: inline bool locked   (void) { return (data.lock); }
-    public:        bool check    (void);
+    public:        bool check    (bool cleared);
 
   };
 
@@ -419,7 +458,7 @@
 
     // Modifiers.
     public: void  obstacle (CRect &rect, int z);
-    public: void  check    (void);
+    public: void  check    (bool cleared);
 
   };
 
@@ -448,10 +487,10 @@
     public: CMatrixPri (CDRGrid *drgrid) : TMatrix<char>(drgrid) { }
 
     // Modifiers.
-    public: void clear    (void);
-    public: void load     (CNet &net, bool global, int expand=0);
-    public: bool take     (int pri, int index);
-    public: void findfree (int index, CNet &net);
+    public: void clear       (void);
+    public: void load        (CNet &net, bool global, int expand=0);
+    public: bool take        (int pri, int index);
+    public: void findfree    (int index, CNet &net);
 
     // Internal methods.
     private: char  nextPri (char curpri);
diff --git a/alliance/src/nero/src/MNet.cpp b/alliance/src/nero/src/MNet.cpp
index 5cef2e8c..d5bcc44d 100644
--- a/alliance/src/nero/src/MNet.cpp
+++ b/alliance/src/nero/src/MNet.cpp
@@ -1,7 +1,7 @@
 
 // -*- C++ -*-
 //
-// $Id: MNet.cpp,v 1.4 2002/10/24 07:51:33 hcl Exp $
+// $Id: MNet.cpp,v 1.5 2002/10/29 18:46:03 jpc Exp $
 //
 //  /----------------------------------------------------------------\ 
 //  |                                                                |
@@ -217,21 +217,98 @@ void  CTerm::newaccess (CRect &rect, int z, int ident, CNet *net)
 void  CTerm::lockalone (bool global)
 {
   CDRGrid::iterator  coord;
-                int  zCoord, zMax, z;
+  CDRGrid::iterator  coord2;
+                int  z, i;
+               bool  adjust;
 
 
   if (nodes.size() != 1) return;
 
   coord  = nodes.back ();
-  zCoord = coord.z();
-  zMax   = min(coord._drgrid->Z - 1, 3);
+  coord2 = coord;
 
-  if ( (zCoord > 0) && !global ) return;
+  if ( (coord.z() > 0) && !global ) return;
+  if (  coord.onAB()) return;
 
-  for (z = (global) ? zMax : 1; z > zCoord; z--) {
+  //cerr << "+ locking lone terminal : " << coord.node().data.owner->name
+  //     << " at " << coord
+  //     << endl;
+
+  // All terminal case, eat up z=1 (ALU2) if not already took.
+  if (coord.z() == 0) {
+    // Go to z=1 (ALU2).
+    //cerr << "+   locking z=1          " << coord << endl;
     newaccess ( coord.x()
               , coord.y()
-              , z
+              , 1
+              , coord.node().getid()
+              , coord.node().data.owner
+              );
+
+    coord2.top();
+  }
+
+  if (!global) return;
+
+
+  if (coord.z() < 2) {
+    // Go to z=2 (ALU3).
+    //cerr << "+   locking z=2          " << coord2 << endl;
+    newaccess ( coord2.x()
+              , coord2.y()
+              , 2
+              , coord.node().getid()
+              , coord.node().data.owner
+              );
+  }
+
+
+  // Global terminal : when zupper=4, find the nearest VIA on the
+  // double pitch grid.
+
+  // Is the terminal in ALU3 (or less).
+  if ( (coord.z() < 3) && (coord.zupper () == 4) ) {
+    if ( coord2.y() % 2 ) {
+      // We are not on the double pitch grid. Try to go there.
+      // Look for up and down grid node.
+      adjust = true;
+
+      for (i = 0; i < 3; i++) {
+        switch (i) {
+          case 0: coord2.dy (+1); break;
+          case 1: coord2.dy (-2); break;
+        }
+
+        // Neither node are accessibles, we are probably doomed ...
+        if (i == 2) { coord2.dy (+1); adjust = false; break; }
+
+        if (coord2.inside()) {
+          if (    !coord2.node().data.obstacle
+              &&  (   (coord2.node().data.owner == NULL )
+                   || (coord2.node().data.owner == coord.node().data.owner) ) )
+            { break; }
+        }
+      }
+
+      if (adjust) {
+        // Adjust to the double grid pitch to z=2 (ALU3).
+        //cerr << "+   locking z=2 (ADJUST) " << coord2 << endl;
+        newaccess ( coord2.x()
+                  , coord2.y()
+                  , 2
+                  , coord.node().getid()
+                  , coord.node().data.owner
+                  );
+      }
+    }
+  }
+
+  if (coord.z() < 4) {
+    // Go to z=3 (ALU3).
+    //cerr << "+   locking z=3          " << coord2 << endl;
+    newaccess ( coord2.x()
+              , coord2.y()
+              , 3
               , coord.node().getid()
               , coord.node().data.owner
               );
diff --git a/alliance/src/nero/src/MPri.cpp b/alliance/src/nero/src/MPri.cpp
index 3b3581bb..9b95e7e5 100644
--- a/alliance/src/nero/src/MPri.cpp
+++ b/alliance/src/nero/src/MPri.cpp
@@ -1,7 +1,7 @@
 
 // -*- C++ -*-
 //
-// $Id: MPri.cpp,v 1.4 2002/10/24 07:51:33 hcl Exp $
+// $Id: MPri.cpp,v 1.5 2002/10/29 18:46:03 jpc Exp $
 //
 //  /----------------------------------------------------------------\ 
 //  |                                                                |
@@ -47,6 +47,15 @@ void  CMatrixPri::findfree (int index, CNet &net)
   cy     = _drgrid->y(index);
   coord  = _drgrid->origin;
 
+  // Check for blocked upper nodes.
+  other = (*_drgrid->nodes)[index].data.owner;
+
+  if (    ! (*_drgrid->nodes)[index].data.obstacle
+      && ((other == NULL) || (other == &net)) )
+    return;
+
+  cdebug << "Looking for an escape!\n" << "\n";
+
   while (!freed) {
     radius += 1;
 
@@ -174,15 +183,7 @@ void CMatrixPri::load (CNet &net, bool global, int expand)
         // Enable z=1 (in case of global signal, no effet otherwise).
         if (coord.z() < _drgrid->Z - 1) (*this)[ coord.dz(1) ] = (char)1; 
 
-        if (global) {
-          // Check for blocked upper nodes.
-          other = (*_drgrid->nodes)[coord].data.owner;
-          if (    (*_drgrid->nodes)[coord].data.obstacle
-              || ((other != NULL) && (other != &net)) ) {
-            cdebug << "Looking for an escape!\n" << "\n";
-            findfree (coord, net);
-          }
-        }
+        if (global) findfree (coord, net);
 
         continue;
       }
@@ -190,29 +191,14 @@ void CMatrixPri::load (CNet &net, bool global, int expand)
       (*this)[ coord.dz(1) ] = nextPri (currentPri); 
       nextBorder->push (new CDRGrid::iterator (coord));
 
-      if (global) {
-        // Check for blocked upper nodes.
-        other = (*_drgrid->nodes)[coord].data.owner;
-        if (    (*_drgrid->nodes)[coord].data.obstacle
-            || ((other != NULL) && (other != &net)) ) {
-          cdebug << "Looking for an escape!\n" << "\n";
-          findfree (coord, net);
-        }
-      }
+      if (global) findfree (coord, net);
         
       // Enable z=2 (in case of global signal, no effet otherwise).
       (*this)[ coord.dz(1) ] = (char)1; 
 
       // Look if the upper node is blocked, in that case expand the
       // allowed zone till a non-blocked node is found.
-      if (global) {
-        other = (*_drgrid->nodes)[coord].data.owner;
-        if (    (*_drgrid->nodes)[coord].data.obstacle
-            || ((other != NULL) && (other != &net)) ) {
-          cdebug << "Looking for an escape!\n" << "\n";
-          findfree (coord, net);
-        }
-      }
+      if (global) findfree (coord, net);
     }
   }
 
diff --git a/alliance/src/nero/src/RBox.cpp b/alliance/src/nero/src/RBox.cpp
index e439b949..5819b890 100644
--- a/alliance/src/nero/src/RBox.cpp
+++ b/alliance/src/nero/src/RBox.cpp
@@ -1,7 +1,7 @@
 
 // -*- C++ -*-
 //
-// $Id: RBox.cpp,v 1.1 2002/10/02 21:23:48 jpc Exp $
+// $Id: RBox.cpp,v 1.2 2002/10/29 18:46:03 jpc Exp $
 //
 //  /----------------------------------------------------------------\ 
 //  |                                                                |
@@ -57,6 +57,7 @@ CRBox::CRBox (void)
   drgrid    = NULL;
   netsched  = NULL;
   loaded    = false;
+  insave    = false;
 }
 
 
@@ -82,7 +83,7 @@ CRBox::CRBox (int rtype, bool debug)
   // Creating routing matrix.
   cdebug << "  Routing matrix size := (10, 15, 5)\n";
 
-  drgrid = new CDRGrid (X, Y, Z);
+  drgrid = new CDRGrid (X, Y, Z, 4);
 
 
   // Adding signal "sig_one".
diff --git a/alliance/src/nero/src/RDefs.h b/alliance/src/nero/src/RDefs.h
index c7590dc4..7d9acf0a 100644
--- a/alliance/src/nero/src/RDefs.h
+++ b/alliance/src/nero/src/RDefs.h
@@ -1,7 +1,7 @@
 
 // -*- C++ -*-
 //
-// $Id: RDefs.h,v 1.1 2002/10/02 21:23:48 jpc Exp $
+// $Id: RDefs.h,v 1.2 2002/10/29 18:46:03 jpc Exp $
 //
 // /-----------------------------------------------------------------\ 
 // |                                                                 |
@@ -43,6 +43,7 @@
     public: CDRGrid    *drgrid;
     public: MNet        nets;
     public: bool        loaded;
+    public: bool        insave;
     public: bool        rglobal;
 
     // MBK dedicated Attributes.
@@ -59,8 +60,8 @@
     // Modifiers.
     public: CNet *getnet  (string &signame);
     public: CNet *getnet  (char *signame);
-    public: void  mbkload (MBK::CFig *mbkfig, int z, int rtype);
-    public: void  mbksave (string &name);
+    public: void  mbkload (MBK::CFig *mbkfig, int z, int zup, int rtype);
+    public: void  mbksave (string &name) throw (except_done);
     public: void  route   (void);
 
   };
diff --git a/alliance/src/nero/src/RMBK.cpp b/alliance/src/nero/src/RMBK.cpp
index da283a79..cd453132 100644
--- a/alliance/src/nero/src/RMBK.cpp
+++ b/alliance/src/nero/src/RMBK.cpp
@@ -1,7 +1,7 @@
 
 // -*- C++ -*-
 //
-// $Id: RMBK.cpp,v 1.4 2002/10/17 21:57:27 jpc Exp $
+// $Id: RMBK.cpp,v 1.5 2002/10/29 18:46:03 jpc Exp $
 //
 //  /----------------------------------------------------------------\ 
 //  |                                                                |
@@ -33,7 +33,7 @@
 // -------------------------------------------------------------------
 // Modifier  :  "CRBox::mbkload()".
 
-void  CRBox::mbkload (MBK::CFig *mbkfig, int z, int rtype)
+void  CRBox::mbkload (MBK::CFig *mbkfig, int z, int zup, int rtype)
 {
     MBK::MIns::iterator   itIns, endInstances, endOrphans;
   MBK::MLosig::iterator   endSig;
@@ -105,7 +105,7 @@ void  CRBox::mbkload (MBK::CFig *mbkfig, int z, int rtype)
          << mX << "," << mY << "," << mZ << "].\n";
 
   // Allocating the routing grid.
-  drgrid = new CDRGrid (mX, mY, mZ);
+  drgrid = new CDRGrid (mX, mY, mZ, zup);
 
 
   rect = new MBK::CXRect (fig->XAB1(), fig->YAB1());
@@ -371,31 +371,31 @@ void  CRBox::mbkload (MBK::CFig *mbkfig, int z, int rtype)
     }
   }
 
-  // On routing level above ALU4, use only half of the tracks.
+  // On routing level above zupper (ALU4), use only half of the tracks.
+  for (zz = zup; zz < mZ; zz++) {
+    switch (zz % 2) {
+      case 0:
+        // Vertical tracks.
+        for (x = 2; x < mX; x += 2) {
+          for (y = 1; y < mY - 1; y++) {
+            node = &( coord.set(x,y,zz).node() );
 
-  // Vertical tracks.
-  for (zz = 4; zz < mZ; zz += 2) {
-    for (x = 2; x < mX; x += 2) {
-      for (y = 1; y < mY - 1; y++) {
-        node = &( coord.set(x,y,zz).node() );
-
-        if ( !node->terminal() ) node->data.obstacle = true;
-      }
+            if ( !node->terminal() ) node->data.obstacle = true;
+          }
+        }
+        break;
+      case 1:
+        // Horizontal tracks.
+        for (y = 2; y < mY; y += 2) {
+          for (x = 1; x < mX; x++) {
+            node = &( coord.set(x,y,zz).node() );
+            if ( !node->terminal() ) node->data.obstacle = true;
+          }
+        }
+        break;
     }
   }
 
-  // Horizontal tracks.
-  for (zz = 5; zz < mZ; zz += 2) {
-    for (y = 2; y < mY; y += 2) {
-      for (x = 1; x < mX; x++) {
-        node = &( coord.set(x,y,zz).node() );
-
-        if ( !node->terminal() ) node->data.obstacle = true;
-      }
-    }
-  }
-
-
 
   // This flag ensure that a figure has been successfully loaded.
   loaded = true;
@@ -409,14 +409,14 @@ void  CRBox::mbkload (MBK::CFig *mbkfig, int z, int rtype)
 // -------------------------------------------------------------------
 // Modifier  :  "CRBox::mbksave()".
 
-void  CRBox::mbksave (string &name)
+  void  CRBox::mbksave (string &name) throw (except_done)
 {
-                int  x, y, z, mX, mY, mZ;
+                int  x, y, z, mX, mY, mZ, pitch, spaceVIA;
                bool  inseg;
               CRect  rect;
   CDRGrid::iterator  coord;
               CNode *node;
-               CNet *pNextNet, *pNet;
+               CNet *pNextNet, *pNet, *pNetTop, *pNetBot;
     MBK::phseg_list  seg;
     MBK::phvia_list  via;
     MNet::iterator   itNet, endNet;
@@ -429,6 +429,11 @@ void  CRBox::mbksave (string &name)
       
     return;
   }
+
+  if (insave) throw except_done ();
+
+  insave = true;
+
   cmess2 << "\n";
   cmess1 << "  o  Dumping routing grid.\n";
 
@@ -578,12 +583,86 @@ void  CRBox::mbksave (string &name)
   via.DX = 0;
   via.DY = 0;
 
+  // Plane loop for VIAs.
+  for (z = 1; z < mZ; z++) {
+    // Track loop for VIAs.
+    if (z >= drgrid->zupper) pitch = 2;
+    else                     pitch = 1;
+
+    if (z % 2) {
+      // z=1 (ALU2) : horizontal tracks.
+      for (y = 1; y < mY; y += pitch) {
+        for (x = 0, spaceVIA = 2; x < mX; x++, spaceVIA++) {
+          // Bottom node.
+          pNetBot = NULL;
+          node = & ( coord.set(x,y,z-1).node() );
+          if ( !coord.isnodehole() && coord.inside() )
+            pNetBot = node->data.owner;
+
+          // Top node.
+          pNetTop = NULL;
+          node = & ( coord.set(x,y,z).node() );
+          if ( !coord.isnodehole() && coord.inside() )
+            pNetTop = node->data.owner;
+
+          // Are the top & bottom nodes belonging to the same net ?
+          if ( (pNetBot != NULL) && (pNetBot == pNetTop) ) {
+            if (spaceVIA < pitch) continue;
+
+            via.TYPE = MBK::env.z2via (z);
+            via.XVIA = fig->XAB1() + x * D::X_GRID;
+            via.YVIA = fig->YAB1() + y * D::Y_GRID;
+            via.NAME = MBK::namealloc(pNetTop->name.c_str ());
+
+            fig->addphvia (via);
+
+            spaceVIA = 0;
+          }
+        }
+      }
+    } else {
+      // z=2 (ALU3) : vertical tracks.
+      for (x = 1; x < mX; x += pitch) {
+        for (y = 0, spaceVIA = 2; y < mY; y++, spaceVIA++) {
+          // Bottom node.
+          pNetBot = NULL;
+          node = & ( coord.set(x,y,z-1).node() );
+          if ( !coord.isnodehole() && coord.inside() )
+            pNetBot = node->data.owner;
+
+          // Top node.
+          pNetTop = NULL;
+          node = & ( coord.set(x,y,z).node() );
+          if ( !coord.isnodehole() && coord.inside() )
+            pNetTop = node->data.owner;
+
+          // Are the top & bottom nodes belonging to the same net ?
+          if ( (pNetBot != NULL) && (pNetBot == pNetTop) ) {
+            if (spaceVIA < pitch) continue;
+
+            via.TYPE = MBK::env.z2via (z);
+            via.XVIA = fig->XAB1() + x * D::X_GRID;
+            via.YVIA = fig->YAB1() + y * D::Y_GRID;
+            via.NAME = MBK::namealloc(pNetTop->name.c_str ());
+
+            fig->addphvia (via);
+
+            spaceVIA = 0;
+          }
+        }
+      }
+    }
+  }
+
+# if 0
   // Plane loop for VIAs.
   for (x = 0; x < mX; x++) {
     for (y = 0; y < mY; y++) {
-
       // Loop on Z axis.
       for (z = 1; z < mZ; z++) {
+        if ( (z >= drgrid->zupper) && ( (x % 2) || (y % 2) ) )
+          break;
+
         node = & ( coord.set(x,y,z).node() );
         if (coord.inside()) pNet = node->data.owner;
         else                pNet = NULL;
@@ -602,6 +681,7 @@ void  CRBox::mbksave (string &name)
       } // End of Z axis loop.
     }
   } // End of plane loop for VIAs.
+# endif
 
 
   // Special case of nets with only one terminal.
diff --git a/alliance/src/nero/src/nero.cpp b/alliance/src/nero/src/nero.cpp
index f5303f2b..aaac0845 100644
--- a/alliance/src/nero/src/nero.cpp
+++ b/alliance/src/nero/src/nero.cpp
@@ -1,7 +1,7 @@
 
 // -*- C++ -*-
 //
-// $Id: nero.cpp,v 1.2 2002/10/13 14:22:47 jpc Exp $
+// $Id: nero.cpp,v 1.3 2002/10/29 18:46:03 jpc Exp $
 //
 //  /----------------------------------------------------------------\ 
 //  |                                                                |
@@ -40,7 +40,8 @@ namespace {
   // ---------------------------------------------------------------
   // Local functions.
 
-  static void print_help (void);
+  static void help   (void);
+  static void serial (void);
 
 
 
@@ -51,9 +52,9 @@ namespace {
 
 
 // -------------------------------------------------------------------
-// Function  :  "print_help()".
+// Function  :  "help()".
 
-static void print_help (void)
+static void help (void)
 {
   cout << "\n"
        << "  o  Usage : \"nero [-h] [-v] [-V] [-c] [-2] [-3] [-4] [-5] [-6]\n"
@@ -86,6 +87,17 @@ static void print_help (void)
 }
 
 
+
+
+// -------------------------------------------------------------------
+// Function  :  "serial()".
+
+static void serial (void)
+{
+  cout << "                                S/N 20021028.1\n";
+}
+
+
   // ---------------------------------------------------------------
   // End of Local Namespace.
 
@@ -156,11 +168,12 @@ int  main (int argc, char *argv[])
                           , "2002"
                           , ALLIANCE_VERSION
                           );
+      serial ();
       cmess1 << "\n";
     }
 
     if (options["h"]->parsed) {
-      print_help ();
+      help ();
       exit (0);
     }
 
@@ -169,7 +182,7 @@ int  main (int argc, char *argv[])
       cerr << "  Missing mandatory argument <netlist> or <routed> (or both)\n";
       cerr << "\n";
 
-      print_help ();
+      help ();
 
       throw except_done ();
     }
@@ -204,13 +217,21 @@ int  main (int argc, char *argv[])
     crbox = new CRBox ();
     //crbox = new CRBox (global, true);
     //cdebug.on ();
-    crbox->mbkload (fig, layers, global);
+    crbox->mbkload (fig, layers, 4, global);
     crbox->route ();
     //cdebug.off ();
     crbox->mbksave (name_routed);
   }
 
 
+  catch (e_zupper &e) {
+    cerr << "\n\n"
+         << "  First \"double pitch\" layer must be at least equal to ALU5 "
+         << "(here : " << MBK::env.z2alu (e.zupper) << ").\n\n"
+         << endl;
+
+    exit (1);
+  }
   catch (bad_grab &e) {
     cerr << herr ("\n");
     cerr << "  Net \"" << e.netName << "\" attempt to grab node ("