diff --git a/vlsisapd/openChams/CMakeLists.txt b/vlsisapd/openChams/CMakeLists.txt
index 515100d3..1865776c 100644
--- a/vlsisapd/openChams/CMakeLists.txt
+++ b/vlsisapd/openChams/CMakeLists.txt
@@ -1,7 +1,7 @@
 INCLUDE_DIRECTORIES(${CHAMS_SOURCE_DIR}/openChams ${LIBXML2_INCLUDE_DIR})
 
-SET ( includes Circuit.h   Netlist.h   Instance.h   Net.h   Name.h   Parameters.h )
-SET ( cpps     Circuit.cpp Netlist.cpp Instance.cpp Net.cpp Name.cpp Parameters.cpp )
+SET ( includes Circuit.h   Netlist.h   Instance.h   Net.h   Name.h   Parameters.h   Schematic.h OpenChamsException.h )
+SET ( cpps     Circuit.cpp Netlist.cpp Instance.cpp Net.cpp Name.cpp Parameters.cpp Schematic.cpp )
 
 ADD_LIBRARY(openChams SHARED ${cpps})
 
diff --git a/vlsisapd/openChams/Circuit.cpp b/vlsisapd/openChams/Circuit.cpp
index af0dc771..5cbefdad 100644
--- a/vlsisapd/openChams/Circuit.cpp
+++ b/vlsisapd/openChams/Circuit.cpp
@@ -11,9 +11,11 @@
 #include <fstream>
 #include <sstream>
 #include <string>
+#include <algorithm>
 using namespace std;
 
 #include "Circuit.h"
+#include "OpenChamsException.h"
 
 namespace {
 	template<class T> T getValue(xmlChar* str) {
@@ -31,9 +33,42 @@ static bool readCircuitParametersDone = false;
 static bool readNetListDone = false;
 static bool readInstancesDone = false;
 static bool readNetsDone = false;
+static bool readSchematicDone = false;
     
-Circuit::Circuit(Name name, Name techno) : _name(name), _techno(techno) {}
+Circuit::Circuit(Name name, Name techno) : _name(name), _techno(techno), _netlist(NULL), _schematic(NULL) {
+    readCircuitParametersDone = false;
+    readNetListDone           = false;
+    readInstancesDone         = false;
+    readNetsDone              = false;
+    readSchematicDone         = false;
+}
 
+void Circuit::check_uppercase(string& str, vector<string>& compares, string message) {
+    transform(str.begin(), str.end(), str.begin(), ::toupper);
+    bool equal = false;
+    for (size_t i = 0 ; i < compares.size() ; i++) {
+        if (str == compares[i]) {
+            equal = true;
+        }
+    }
+    if (!equal) {
+        throw OpenChamsException(message);
+    }
+}
+    
+void Circuit::check_lowercase(string& str, vector<string>& compares, string message) {
+    transform(str.begin(), str.end(), str.begin(), ::tolower);
+    bool equal = false;
+    for (size_t i = 0 ; i < compares.size() ; i++) {
+        if (str == compares[i]) {
+            equal = true;
+        }
+    }
+    if (!equal) {
+        throw OpenChamsException(message);
+    }
+}
+    
 Name Circuit::readParameter(xmlNode* node, double& value) {
     xmlChar* paramNameC = xmlGetProp(node, (xmlChar*)"name");
     xmlChar* valueC     = xmlGetProp(node, (xmlChar*)"value");
@@ -42,8 +77,8 @@ Name Circuit::readParameter(xmlNode* node, double& value) {
         value = ::getValue<double>(valueC);
         return name;
     } else {
-        cerr << "[ERROR] 'parameter' node must have 'name' and 'value' properties." << endl;
-        return Name("");
+        throw OpenChamsException("[ERROR] 'parameter' node must have 'name' and 'value' properties.");
+        //return Name("");
     }
 }
     
@@ -53,8 +88,8 @@ Name Circuit::readConnector(xmlNode* node) {
         Name name((const char*)connectorNameC);
         return name;
     } else {
-        cerr << "[ERROR] 'connector' node must have 'name' property." << endl;
-        return Name("");
+        throw OpenChamsException("[ERROR] 'connector' node must have 'name' property.");
+        //return Name("");
     }
 }
     
@@ -126,15 +161,24 @@ Instance* Circuit::readInstance(xmlNode* node, Netlist* netlist) {
     xmlChar* iNameC  = xmlGetProp(node, (xmlChar*)"name");
     xmlChar* iModelC = xmlGetProp(node, (xmlChar*)"model");
     xmlChar* iMOSC   = xmlGetProp(node, (xmlChar*)"mostype");
+    xmlChar* iSBCC   = xmlGetProp(node, (xmlChar*)"sourceBulkConnected");
     Instance* inst = NULL;
-    if (iNameC && iModelC && iMOSC) {
+    if (iNameC && iModelC && iMOSC && iSBCC) {
         Name instanceName((const char*)iNameC);
         Name modelName((const char*)iModelC);
-        Name mosName((const char*)iMOSC);
-        inst = new Instance(instanceName, modelName, mosName, netlist);
+        string mosStr((const char*)iMOSC);
+        string mosComp[2] = {"NMOS", "PMOS"};
+        vector<string> mosComps (mosComp, mosComp+2);
+        check_uppercase(mosStr, mosComps, "[ERROR] In 'instance', 'mostype' must be 'NMOS' or 'PMOS'.");
+        string sourceBulkStr((const char*)iSBCC);
+        string sbcComp[4] = {"true", "false", "on", "off"};
+        vector<string> sbcComps(sbcComp, sbcComp+4);
+        check_lowercase(sourceBulkStr, sbcComps, "[ERROR] In 'instance', 'sourceBulkConnected' must 'true', 'false', 'on' or 'off'.");
+        bool sourceBulkConnected = ((sourceBulkStr == "true") || (sourceBulkStr == "on")) ? true : false;
+        inst = new Instance(instanceName, modelName, Name(mosStr), sourceBulkConnected, netlist);
     } else {
-        cerr << "[ERROR] 'instance' node must have 'name', 'model' and 'mos' properties." << endl;
-        return inst;
+        throw OpenChamsException("[ERROR] 'instance' node must have 'name', 'model', 'mostype' and 'sourceBulkConnected' properties.");
+        //return inst;
     }
 
     xmlNode* child = node->children;
@@ -205,14 +249,20 @@ Net* Circuit::readNet(xmlNode* node, Netlist* netlist) {
     Net* net = NULL;
     if (nNameC && nTypeC && nExternC) {
         Name netName((const char*)nNameC);
-        Name typeName((const char*)nTypeC);
+        string typeStr((const char*)nTypeC);
+        string typeComp[3] = {"power", "ground", "logical"};
+        vector<string> typeComps(typeComp, typeComp+3);
+        check_lowercase(typeStr, typeComps, "[ERROR] In 'net', 'type' must be 'power', 'ground' or 'logical'.");
         string externStr((const char*)nExternC);
-        bool isExternal = (externStr == "True") ? true : false;
-        net = new Net(netName, typeName, isExternal, netlist);
+        string extComp[4] = {"true", "false", "on", "off"};
+        vector<string> extComps(extComp, extComp+4);
+        check_lowercase(externStr, extComps, "[ERROR] In 'net', 'isExternal' must be 'true', 'false', 'on' or 'off'.");
+        bool isExternal = ((externStr == "true") || (externStr == "on")) ? true : false;
+        net = new Net(netName, Name(typeStr), isExternal, netlist);
         netlist->addNet(net);
     } else {
-        cerr << "[ERROR] 'net' node must have 'name', 'type' and 'isExternal' properties." << endl;
-        return net;
+        throw OpenChamsException("[ERROR] 'net' node must have 'name', 'type' and 'isExternal' properties.");
+        //return net;
     }
     
     xmlNode* child = node->children;
@@ -237,23 +287,77 @@ void Circuit::readNetConnector(xmlNode* node, Net* net) {
         Name cName((const char*)connectorNameC);
         Instance* inst = net->getNetlist()->getInstance(iName);
         if (!inst) {
-            cerr << "[ERROR] no instance named \"" << iName.getString() << "\" in connector of net \"" << net->getName().getString() << "\"." << endl;
-            return;
+            string error("[ERROR] no instance named \"");
+            error += iName.getString();
+            error += "\" in connector of net \"";
+            error += net->getName().getString();
+            error += "\".";
+            throw OpenChamsException(error);
+            //return;
         }
         inst->connect(cName, net->getName());
         net->connectTo(iName, cName);
     } else {
-        cerr << "[ERROR] 'connector' node must have 'instance' and 'name' properties (for net)." << endl;
+        throw OpenChamsException("[ERROR] 'connector' node must have 'instance' and 'name' properties (for net).");
     }
 }
     
-Circuit* Circuit::readFromFile(string filePath) {
+void Circuit::readSchematic(xmlNode* node) {
+    if (readSchematicDone) {
+        cerr << "[WARNING] Only one 'schematic' node is allowed in circuit, others will be ignored." << endl;
+        return;
+    }
+    xmlChar* zoomC = xmlGetProp(node, (xmlChar*)"zoom");
+    double zoom = 1.0;
+    if (zoomC) {
+        zoom = ::getValue<double>(zoomC);
+    } else {
+        throw OpenChamsException("[ERROR] 'schematic' node must have 'zoom' property.");
+    }
+
+    Schematic* schematic = new Schematic(this, zoom);
+    xmlNode* child = node->children;
+    for (xmlNode* node = child; node; node = node->next) {
+        if (node->type == XML_ELEMENT_NODE) {
+            if (xmlStrEqual(node->name, (xmlChar*)"instance")) {
+                readInstanceSchematic(node, schematic);
+            } else {
+                cerr << "[WARNING] Only 'instance' nodes are allowed in 'schematic', others will be ignored." << endl;
+            }
+        }
+    }
+    readSchematicDone = true;
+    _schematic = schematic;
+}
+    
+void Circuit::readInstanceSchematic(xmlNode* node, Schematic* schematic) {
+    xmlChar* nameC = xmlGetProp(node, (xmlChar*)"name");
+    xmlChar* xC    = xmlGetProp(node, (xmlChar*)"x");
+    xmlChar* yC    = xmlGetProp(node, (xmlChar*)"y");
+    xmlChar* symC  = xmlGetProp(node, (xmlChar*)"sym");
+    if (nameC && xC && yC && symC) {
+        Name   iName((const char*)nameC);
+        double x = ::getValue<double>(xC);
+        double y = ::getValue<double>(yC);
+        string symStr((const char*)symC);
+        string symComp[8] = {"ID", "R1", "R2", "R3", "MX", "XR", "MY", "YR"};
+    	vector<string> symComps (symComp, symComp+8);
+        check_uppercase(symStr, symComps, "[ERROR] In 'schematic/instance', 'sym' must be 'ID', 'R1', 'R2', 'R3', 'MX', 'XR', 'MY' or 'YR'.");
+        schematic->addInstance(iName, x, y, Name(symStr));
+    } else {
+        throw OpenChamsException("[ERROR] 'instance' node in 'schematic' must have 'name', 'x', 'y' and 'sym' properties.");
+    }
+}
+    
+Circuit* Circuit::readFromFile(const string filePath) {
     LIBXML_TEST_VERSION;
     Circuit* cir = NULL;
     xmlDoc* doc = xmlReadFile(filePath.c_str(), NULL, 0);
     if (doc == NULL) {
-        cerr << "[ERROR] Failed to parse: " << filePath << endl;
-        return NULL;
+        string error ("[ERROR] Failed to parse: ");
+        error += filePath;
+        throw OpenChamsException(error);
+        //return NULL;
     }
     xmlNode* rootElement = xmlDocGetRootElement(doc);
     if (rootElement->type == XML_ELEMENT_NODE && xmlStrEqual(rootElement->name, (xmlChar*)"circuit")) {
@@ -265,7 +369,7 @@ Circuit* Circuit::readFromFile(string filePath) {
             Name technoName  ((const char*)technoNameC);
             cir = new Circuit(circuitName, technoName);
         } else {
-            cerr << "[ERROR] 'circuit' node must have 'name' and 'techno' properties." << endl;
+            throw OpenChamsException("[ERROR] 'circuit' node must have 'name' and 'techno' properties.");
             return NULL;
         }
 
@@ -279,9 +383,15 @@ Circuit* Circuit::readFromFile(string filePath) {
                 if (xmlStrEqual(node->name, (xmlChar*)"netlist")) {
                     cir->readNetList(node);
                 }
+                if (xmlStrEqual(node->name, (xmlChar*)"schematic")) {
+                    cir->readSchematic(node);
+                }
             }
         }
     }
+    if (!readNetListDone) {
+        throw OpenChamsException("[ERROR] no <netlist> section was found in parsed file !");
+    }
     return cir;
 }
     
@@ -290,45 +400,49 @@ bool Circuit::writeToFile(string filePath) {
     file.open(filePath.c_str());
     // checks before do anything
     if (!_netlist) {
-        cerr << "[ERROR] Cannot writeToFile since no netlist is defined !" << endl;
-        return false;
+        throw OpenChamsException("[ERROR] Cannot writeToFile since no netlist is defined !");
+        //return false;
     }    
     if (_netlist->hasNoInstances()) {
-        cerr << "[ERROR] Cannot writeToFile since no instance is defined in netlist !" << endl;
-        return false;
+        throw OpenChamsException("[ERROR] Cannot writeToFile since no instance is defined in netlist !");
+        //return false;
     }
     if (_netlist->hasNoNets()) {
-        cerr << "[ERROR] Cannot writeToFile since no net is defined in netlist !" << endl;
-        return false;
+        throw OpenChamsException("[ERROR] Cannot writeToFile since no net is defined in netlist !");
+        //return false;
     }
     
     file << "<?xml version=\"1.0\" encoding=\"UTF-8\" ?>" << endl
          << "<circuit name=\"" << _name.getString() << "\" techno=\"" << _techno.getString() << "\">" << endl;
     if (!_params.isEmpty()) {
         file << "  <parameters>" << endl;
-    	for (map<Name, double>::iterator it = _params.getFirstIt() ; it != _params.getLastIt() ; ++it) {
+    	for (map<Name, double>::const_iterator it = _params.getValues().begin() ; it != _params.getValues().end() ; ++it) {
         	file << "    <parameter name=\"" << (*it).first.getString() << "\" value=\"" << (*it).second << "\"/>" << endl;
     	}
         file << "  </parameters>" << endl;
     }
     file << "  <netlist>" << endl
          << "    <instances>" << endl;
-    for (vector<Instance*>::iterator it = _netlist->getFirstInstanceIt() ; it != _netlist->getLastInstanceIt() ; ++it) {
+    for (vector<Instance*>::const_iterator it = _netlist->getInstances().begin() ; it != _netlist->getInstances().end() ; ++it) {
         Instance* inst = (*it);
         if (inst->hasNoConnectors()) {
-            cerr << "[ERROR] Cannot writeToFile since instance (" << inst->getName().getString() << ") has no connectors !" << endl;
-            return false;
+            string error("[ERROR] Cannot writeToFile since instance (");
+            error += inst->getName().getString();
+            error += ") has no connectors !";
+            throw OpenChamsException(error);
+            //return false;
         }
-        file << "      <instance name=\"" << inst->getName().getString() << "\" model=\"" << inst->getModel().getString() << "\" mostype=\"" << inst->getMosType().getString() << "\">" << endl;
+        string sourceBulkStr = (inst->isSourceBulkConnected()) ? "True" : "False";
+        file << "      <instance name=\"" << inst->getName().getString() << "\" model=\"" << inst->getModel().getString() << "\" mostype=\"" << inst->getMosType().getString() << "\" sourceBulkConnected=\"" << sourceBulkStr << "\">" << endl;
         file << "        <connectors>" << endl;
-        for (map<Name, Net*>::iterator it = inst->getFirstConnectorIt() ; it != inst->getLastConnectorIt() ; ++it) {
+        for (map<Name, Net*>::const_iterator it = inst->getConnectors().begin() ; it != inst->getConnectors().end() ; ++it) {
             file << "          <connector name=\"" << (*it).first.getString() << "\"/>" << endl;
         }
         file << "        </connectors>" << endl;
         if (!inst->getParameters().isEmpty()) {
             Parameters params = inst->getParameters();
             file << "        <parameters>" << endl;
-            for (map<Name, double>::iterator it = params.getFirstIt() ; it != params.getLastIt() ; ++it) {
+            for (map<Name, double>::const_iterator it = params.getValues().begin() ; it != params.getValues().end() ; ++it) {
                 file << "          <parameter name=\"" << (*it).first.getString() << "\" value=\"" << (*it).second << "\"/>" << endl;
             }
             file << "        </parameters>" << endl;
@@ -337,21 +451,32 @@ bool Circuit::writeToFile(string filePath) {
     }
     file << "    </instances>" << endl
          << "    <nets>" << endl;
-    for (vector<Net*>::iterator it = _netlist->getFirstNetIt() ; it != _netlist->getLastNetIt() ; ++it) {
+    for (vector<Net*>::const_iterator it = _netlist->getNets().begin() ; it != _netlist->getNets().end() ; ++it) {
         Net* net = (*it);
         if (net->hasNoConnectors()) {
-            cerr << "[ERROR] Cannot writeToFile since net (" << net->getName().getString() << ") has no connectors !" << endl;
-            return false;
+            string error("[ERROR] Cannot writeToFile since net (");
+            error += net->getName().getString();
+            error += ") has no connectors !";
+            throw OpenChamsException(error);
+            //return false;
         }
         string externStr = (net->isExternal()) ? "True" : "False";
         file << "      <net name=\"" << net->getName().getString() << "\" type=\"" << net->getType().getString() << "\" isExternal=\"" << externStr << "\">" << endl;
-        for (vector<pair<Name, Name> >::iterator it = net->getFirstConnectionIt() ; it != net->getLastConnectionIt() ; ++it) {
+        for (vector<pair<Name, Name> >::const_iterator it = net->getConnections().begin() ; it != net->getConnections().end() ; ++it) {
             file << "        <connector instance=\"" << (*it).first.getString() << "\" name=\"" << (*it).second.getString() << "\"/>" << endl;
         }
 		file << "      </net>" << endl;
     }
     file << "    </nets>" << endl;
     file << "  </netlist>" << endl;
+    if (_schematic && !_schematic->hasNoInstances()) {
+        file << "  <schematic zoom=\"" << _schematic->getZoom() << "\">" << endl;
+        for (map<Name, Schematic::Infos*>::const_iterator it = _schematic->getInstances().begin() ; it != _schematic->getInstances().end(); ++it ) {
+            Schematic::Infos* infos = (*it).second;
+            file << "    <instance name=\"" << ((*it).first).getString() << "\" x=\"" << infos->getX() << "\" y=\"" << infos->getY() << "\" sym=\"" << infos->getSymetry().getString() << "\"/>" << endl;
+        }
+        file << "  </schematic>" << endl;
+    }
     file << "</circuit>" << endl;
     file.close();
 	return true;        
diff --git a/vlsisapd/openChams/Circuit.h b/vlsisapd/openChams/Circuit.h
index 2fb57d80..5c194c65 100644
--- a/vlsisapd/openChams/Circuit.h
+++ b/vlsisapd/openChams/Circuit.h
@@ -18,19 +18,22 @@
 #include "Netlist.h"
 #include "Instance.h"
 #include "Net.h"
+#include "Schematic.h"
 
 namespace OpenChams {
 class Circuit {
     public:
     Circuit(Name name, Name techno);
     
-    inline Name   getName();
-    inline Name   getTechno();
-    inline double getValue(Name);
-    inline void   addParameter(Name, double);
+    inline Name       getName();
+    inline Name       getTechno();
+    inline double     getValue(Name);
+    inline Netlist*   getNetlist();
+    inline Schematic* getSchematic();
+    inline void       addParameter(Name, double);
     
     bool writeToFile(string filePath);
-    static Circuit* readFromFile(string filePath);
+    static Circuit* readFromFile(const string filePath);
     
 	private:
     Name      readParameter(xmlNode*, double&);
@@ -44,18 +47,25 @@ class Circuit {
     void      readNets(xmlNode*, Netlist*);
     Net*      readNet (xmlNode*, Netlist*);
     void      readNetConnector(xmlNode*, Net*);
+    void      readSchematic(xmlNode*);
+    void      readInstanceSchematic(xmlNode*, Schematic*);
     
+    void      check_uppercase(string& str, vector<string>& compares, string message);
+    void      check_lowercase(string& str, vector<string>& compares, string message);
     
     Name 	   _name;
     Name 	   _techno;
     Parameters _params;
     Netlist*   _netlist;
+    Schematic* _schematic;
 };
     
-inline Name   Circuit::getName()   		   { return _name; }    
-inline Name   Circuit::getTechno()         { return _techno; }
-inline double Circuit::getValue(Name name) { return _params.getValue(name); }
-inline void   Circuit::addParameter(Name name, double value) { _params.addParameter(name, value); }
+inline Name       Circuit::getName()    	   { return _name; }    
+inline Name       Circuit::getTechno()         { return _techno; }
+inline double     Circuit::getValue(Name name) { return _params.getValue(name); }
+inline Netlist*   Circuit::getNetlist()        { return _netlist; };
+inline Schematic* Circuit::getSchematic()      { return _schematic; };
+inline void       Circuit::addParameter(Name name, double value) { _params.addParameter(name, value); }
     
     
 } // namespace IO
diff --git a/vlsisapd/openChams/Instance.cpp b/vlsisapd/openChams/Instance.cpp
index b8b0a5a9..c7fae05f 100644
--- a/vlsisapd/openChams/Instance.cpp
+++ b/vlsisapd/openChams/Instance.cpp
@@ -13,12 +13,14 @@ using namespace std;
 #include "Instance.h"
 #include "Netlist.h"
 #include "Net.h"
+#include "OpenChamsException.h"
 
 namespace OpenChams {
-Instance::Instance(Name name, Name model, Name mosType, Netlist* netlist)
+Instance::Instance(Name name, Name model, Name mosType, bool sourceBulkConnected, Netlist* netlist)
     : _name(name)
     , _model(model)
     , _mosType(mosType)
+    , _sourceBulkConnected(sourceBulkConnected)
     , _netlist(netlist) {}
 
 void Instance::addConnector(Name name) {
@@ -26,8 +28,12 @@ void Instance::addConnector(Name name) {
     map<Name, Net*>::iterator it = _netMap.find(name);
     if (it == _netMap.end())
         _netMap[name] = NULL;
-    else
-        cerr << "[ERROR] The same instance cannot have several connectors with same name (" << name.getString() << ")." << endl;
+    else {
+        string error("[ERROR] The same instance cannot have several connectors with same name (");
+        error += name.getString();
+        error += ").";
+        throw OpenChamsException(error);
+    }
 }
     
 void Instance::connect(Name connectorName, Name netName) {
@@ -37,13 +43,20 @@ void Instance::connect(Name connectorName, Name netName) {
     map<Name, Net*>::iterator it = _netMap.find(connectorName);
     if (it != _netMap.end()) {
         Net* net = _netlist->getNet(netName);
-        if (!net)
-            cerr << "[ERROR] While connecting instance : net (" << netName.getString() << ") does not exist." << endl;
+        if (!net) {
+            string error("[ERROR] While connecting instance : net (");
+            error += netName.getString();
+            error += ") does not exist.";
+            throw OpenChamsException(error);
+        }
         else
             _netMap[connectorName] = net;
     }
-    else
-        cerr << "[ERROR] While connecting instance : connector (" << connectorName.getString() << ") does not exist." << endl;
+    else {
+        string error("[ERROR] While connecting instance : connector (");
+        error += connectorName.getString();
+        error += ") does not exist.";
+        throw OpenChamsException(error);
+    }
 }
-}
-
+}
\ No newline at end of file
diff --git a/vlsisapd/openChams/Instance.h b/vlsisapd/openChams/Instance.h
index 946daef1..379ba863 100644
--- a/vlsisapd/openChams/Instance.h
+++ b/vlsisapd/openChams/Instance.h
@@ -10,9 +10,7 @@
 #ifndef __OPENCHAMS_INSTANCE_H__
 #define __OPENCHAMS_INSTANCE_H__
 
-#include <string>
 #include <map>
-using namespace std;
 
 #include "Name.h"
 #include "Parameters.h"
@@ -22,7 +20,7 @@ class Netlist;
 class Net;
 class Instance {
 	public:
-    Instance(Name name, Name model, Name mosType, Netlist*);
+    Instance(Name name, Name model, Name mosType, bool, Netlist*);
     
     void addConnector(Name);
     void connect(Name connectorName, Name netName);
@@ -33,29 +31,34 @@ class Instance {
     inline Name getName();
     inline Name getModel();
     inline Name getMosType();
+    inline bool isSourceBulkConnected();
     inline Parameters getParameters();
     // pour parcourir les connecteurs
     inline bool hasNoConnectors();
-    inline map<Name, Net*>::iterator getFirstConnectorIt();
-    inline map<Name, Net*>::iterator getLastConnectorIt();
+    //inline map<Name, Net*>::iterator getFirstConnectorIt();
+    //inline map<Name, Net*>::iterator getLastConnectorIt();
+    inline const std::map<Name, Net*>& getConnectors();
         
-private:
+	private:
 	Name 	   		_name;
     Name 	   		_model;
     Name 	   		_mosType;
+    bool            _sourceBulkConnected;
     Netlist*   		_netlist;
     Parameters 		_params;
-    map<Name, Net*> _netMap; //map associant nom de connecteur a un net
+    std::map<Name, Net*> _netMap; //map associant nom de connecteur a un net
 };
 
 inline void Instance::addParameter(Name name, double value) { _params.addParameter(name, value); };
 inline Name Instance::getName() { return _name; };
 inline Name Instance::getModel() { return _model; };
 inline Name Instance::getMosType() { return _mosType; };
+inline bool Instance::isSourceBulkConnected() { return _sourceBulkConnected; };
 inline Parameters Instance::getParameters() { return _params; };
 inline bool Instance::hasNoConnectors() { return (_netMap.size() == 0)? true : false; };
-inline map<Name, Net*>::iterator Instance::getFirstConnectorIt() { return _netMap.begin(); };
-inline map<Name, Net*>::iterator Instance::getLastConnectorIt() { return _netMap.end(); };
+//inline map<Name, Net*>::iterator Instance::getFirstConnectorIt() { return _netMap.begin(); };
+//inline map<Name, Net*>::iterator Instance::getLastConnectorIt() { return _netMap.end(); };
+inline const std::map<Name, Net*>& Instance::getConnectors() { return _netMap; };
     
 } // namespace
 #endif
diff --git a/vlsisapd/openChams/Name.cpp b/vlsisapd/openChams/Name.cpp
index 6aabb04c..dcd973a8 100644
--- a/vlsisapd/openChams/Name.cpp
+++ b/vlsisapd/openChams/Name.cpp
@@ -7,13 +7,15 @@
  *
  */
 
+using namespace std;
+
 #include "Name.h"
 
 namespace OpenChams {
 unsigned long Name::_globalId = 0;
 map<string, unsigned long> Name::_dict;
 
-Name::Name(string str) {
+Name::Name(string str) : _str(NULL) {
     map<string, unsigned long>::iterator it = _dict.find(str);
     if (it != _dict.end()) {
         _id  = (*it).second;
@@ -25,7 +27,7 @@ Name::Name(string str) {
     }
 }
     
-Name::Name(const char* c) {
+Name::Name(const char* c) : _str(NULL) {
     string str(c);
     map<string, unsigned long>::iterator it = _dict.find(str);
     if (it != _dict.end()) {
diff --git a/vlsisapd/openChams/Name.h b/vlsisapd/openChams/Name.h
index b3a63a5b..bad4d10d 100644
--- a/vlsisapd/openChams/Name.h
+++ b/vlsisapd/openChams/Name.h
@@ -12,33 +12,36 @@
 
 #include <string>
 #include <map>
-using namespace std;
+
+#include "OpenChamsException.h"
 
 namespace OpenChams {
 class Name {
     public:
-        Name(string);
-	    Name(const char*);
+    Name(std::string);
+	Name(const char*);
     
-	    bool operator==(const Name&);
-	    bool operator==(const string&);
-	    bool operator<(const Name) const;
+	bool operator==(const Name&);
+	bool operator==(const std::string&);
+	bool operator<(const Name) const;
     
-	    inline const string& getString() const;
+	inline const std::string& getString() const;
         
     private:
-        unsigned long _id;
-        const string *_str;
+    unsigned long _id;
+	const std::string *_str;
     
-    	static map<string, unsigned long> _dict;
-	    static unsigned long              _globalId;
+	static std::map<std::string, unsigned long> _dict;
+	static unsigned long              _globalId;
 };
     
-const string& Name::getString() const{
+inline const std::string& Name::getString() const{
+    if (!_str) {
+        throw OpenChamsException("[ERROR] Name object has no string");
+    }
     return *_str;
 }
 
 } // namespace
-
 #endif
 
diff --git a/vlsisapd/openChams/Net.cpp b/vlsisapd/openChams/Net.cpp
index ede61efa..5cad40c4 100644
--- a/vlsisapd/openChams/Net.cpp
+++ b/vlsisapd/openChams/Net.cpp
@@ -7,6 +7,8 @@
  *
  */
 
+using namespace std;
+
 #include "Net.h"
 #include "Netlist.h"
 
diff --git a/vlsisapd/openChams/Net.h b/vlsisapd/openChams/Net.h
index 4d5cf7b2..e3252752 100644
--- a/vlsisapd/openChams/Net.h
+++ b/vlsisapd/openChams/Net.h
@@ -11,11 +11,9 @@
 #define __OPENCHAMS_NET_H__
 
 #include <vector>
-using namespace std;
 
 #include "Name.h"
 #include "Instance.h"
-//#include "Net.h"
 
 namespace OpenChams {
 class Netlist;
@@ -30,15 +28,16 @@ class Net {
     inline bool     isExternal();
     inline Netlist* getNetlist();
     inline bool     hasNoConnectors();
-    inline vector<pair<Name, Name> >::iterator getFirstConnectionIt();
-    inline vector<pair<Name, Name> >::iterator getLastConnectionIt();
+    //inline vector<pair<Name, Name> >::iterator getFirstConnectionIt();
+    //inline vector<pair<Name, Name> >::iterator getLastConnectionIt();
+    inline const std::vector<std::pair<Name, Name> >& getConnections();
         
     private:
     Name     _name;
     Name     _typeName;
     bool     _isExternal;
     Netlist* _netlist;
-    vector< pair<Name, Name> > _connections; // <instanceName, connectorName>
+    std::vector<std::pair<Name, Name> > _connections; // <instanceName, connectorName>
 };
     
 inline Name Net::getName() { return _name; };
@@ -46,9 +45,10 @@ inline Name Net::getType() { return _typeName; };
 inline bool Net::isExternal() { return _isExternal; };
 inline Netlist* Net::getNetlist() { return _netlist; };
 inline bool Net::hasNoConnectors() { return (_connections.size() == 0)? true : false; };
-inline vector<pair<Name, Name> >::iterator Net::getFirstConnectionIt() { return _connections.begin();};
-inline vector<pair<Name, Name> >::iterator Net::getLastConnectionIt() { return _connections.end();};
-    
+//inline vector<pair<Name, Name> >::iterator Net::getFirstConnectionIt() { return _connections.begin();};
+//inline vector<pair<Name, Name> >::iterator Net::getLastConnectionIt() { return _connections.end();};
+inline const std::vector<std::pair<Name, Name> >& Net::getConnections() { return _connections; };    
+
 } // namespace
 #endif
 
diff --git a/vlsisapd/openChams/Netlist.cpp b/vlsisapd/openChams/Netlist.cpp
index 4bb65299..bdcb4521 100644
--- a/vlsisapd/openChams/Netlist.cpp
+++ b/vlsisapd/openChams/Netlist.cpp
@@ -11,26 +11,35 @@
 #include <algorithm>
 using namespace std;
 
-#include "Netlist.h"
+#include "NetList.h"
 #include "Circuit.h"
+#include "OpenChamsException.h"
 
 namespace OpenChams {
 Netlist::Netlist(Circuit* circuit) : _circuit(circuit) {}
     
 void Netlist::addInstance(Instance* inst) {
-    vector<Instance*>::iterator it = find(_instances.begin(), _instances.end(), inst);
-    if (it != _instances.end())
-        cerr << "[WARNING] Cannot add instance twice in netlist (" << inst->getName().getString() << ")." << endl;
-    else
-        _instances.push_back(inst);
+    for (vector<Instance*>::iterator it = _instances.begin() ; it != _instances.end() ; ++it) {
+        if ((*it)->getName() == inst->getName()) {
+            string error("[ERROR] Cannot define two instances with the same name in netlist (");
+            error += inst->getName().getString();
+            error += ").";
+            throw OpenChamsException(error);
+        }
+    }
+    _instances.push_back(inst);
 }
 
 void Netlist::addNet(Net* net) {
-	vector<Net*>::iterator it = find(_nets.begin(), _nets.end(), net);
-    if (it != _nets.end())
-        cerr << "[WARNING] Cannot add net twice in netlist (" << net->getName().getString() << ")." << endl;
-    else
-        _nets.push_back(net);
+	for (vector<Net*>::iterator it = _nets.begin() ; it != _nets.end() ; ++it ) {
+        if ((*it)->getName() == net->getName()) {
+            string error("[ERROR] Cannot define two nets with the same name in netlist (");
+            error += net->getName().getString();
+            error += ").";
+            throw OpenChamsException(error);
+        }
+    }
+    _nets.push_back(net);
 }
  
 Instance* Netlist::getInstance(Name instanceName) {
@@ -51,3 +60,4 @@ Net* Netlist::getNet(Name netName) {
     return NULL;
 }
 } // namespace
+
diff --git a/vlsisapd/openChams/Netlist.h b/vlsisapd/openChams/Netlist.h
index d491b425..83fb1358 100644
--- a/vlsisapd/openChams/Netlist.h
+++ b/vlsisapd/openChams/Netlist.h
@@ -11,7 +11,6 @@
 #define __OPENCHAMS_NETLIST_H__
 
 #include <vector>
-using namespace std;
 
 #include "Name.h"
 #include "Instance.h"
@@ -32,23 +31,27 @@ class Netlist {
     //pour parcourir les vector
     inline bool hasNoInstances();
     inline bool hasNoNets();
-    inline vector<Instance*>::iterator getFirstInstanceIt();
-    inline vector<Instance*>::iterator getLastInstanceIt();
-    inline vector<Net*>::iterator getFirstNetIt();
-    inline vector<Net*>::iterator getLastNetIt();
-        
+    //inline vector<Instance*>::iterator getFirstInstanceIt();
+    //inline vector<Instance*>::iterator getLastInstanceIt();
+    //inline vector<Net*>::iterator getFirstNetIt();
+    //inline vector<Net*>::iterator getLastNetIt();
+    inline const std::vector<Instance*>& getInstances();
+    inline const std::vector<Net*>& getNets();
+    
     private:
     Circuit*          _circuit;
-    vector<Instance*> _instances;
-    vector<Net*>      _nets;
+    std::vector<Instance*> _instances;
+    std::vector<Net*>      _nets;
 };
     
-inline bool 					   Netlist::hasNoInstances() 	 { return (_instances.size() == 0)? true : false; }
-inline bool 					   Netlist::hasNoNets()      	 { return (_nets.size() == 0)? true : false; }
-inline vector<Instance*>::iterator Netlist::getFirstInstanceIt() { return _instances.begin(); }
-inline vector<Instance*>::iterator Netlist::getLastInstanceIt()  { return _instances.end(); }
-inline vector<Net*>::iterator      Netlist::getFirstNetIt()      { return _nets.begin(); }
-inline vector<Net*>::iterator      Netlist::getLastNetIt()       { return _nets.end(); }
+inline bool 					Netlist::hasNoInstances() { return (_instances.size() == 0)? true : false; }
+inline bool 					Netlist::hasNoNets()      { return (_nets.size() == 0)? true : false; }
+//inline vector<Instance*>::iterator Netlist::getFirstInstanceIt() { return _instances.begin(); }
+//inline vector<Instance*>::iterator Netlist::getLastInstanceIt()  { return _instances.end(); }
+//inline vector<Net*>::iterator      Netlist::getFirstNetIt()      { return _nets.begin(); }
+//inline vector<Net*>::iterator      Netlist::getLastNetIt()       { return _nets.end(); }
+inline const std::vector<Instance*>& Netlist::getInstances()   { return _instances; };
+inline const std::vector<Net*>&      Netlist::getNets()        { return _nets; };
     
 } // namespace
 #endif
diff --git a/vlsisapd/openChams/OpenChamsException.h b/vlsisapd/openChams/OpenChamsException.h
new file mode 100644
index 00000000..d3b422c7
--- /dev/null
+++ b/vlsisapd/openChams/OpenChamsException.h
@@ -0,0 +1,27 @@
+/*
+ *  OpenChamsException.h
+ *  openChams
+ *
+ *  Created by damien dupuis on 20/01/10.
+ *  Copyright 2010 UPMC / LIP6. All rights reserved.
+ *
+ */
+
+#ifndef __OPENCHAMS_EXCEPTION_NET_H__
+#define __OPENCHAMS_EXCEPTION_NET_H__
+
+#include <exception>
+#include <string>
+
+namespace OpenChams {
+class OpenChamsException {
+	public:
+        OpenChamsException(const std::string& what) throw() : _what(what) {}
+        virtual const char* what() const throw() { return _what.c_str(); }
+        virtual ~OpenChamsException() throw() {}
+        
+    private:
+        std::string _what;
+};
+} // namespace
+#endif
\ No newline at end of file
diff --git a/vlsisapd/openChams/Parameters.cpp b/vlsisapd/openChams/Parameters.cpp
index 66345c7c..7f90a81b 100644
--- a/vlsisapd/openChams/Parameters.cpp
+++ b/vlsisapd/openChams/Parameters.cpp
@@ -11,13 +11,16 @@
 using namespace std;
 
 #include "Parameters.h"
+#include "OpenChamsException.h"
 
 namespace OpenChams {
 double Parameters::getValue(Name name) {
     map<Name, double>::iterator it = _params.find(name);
     if (it == _params.end()) {
-        cerr << "[ERROR] No parameters named " << name.getString() << endl;
-        return 0.0;
+        string error("[ERROR] No parameters named ");
+        error += name.getString();
+        throw OpenChamsException(error);
+        //return 0.0;
     }
     return (*it).second;
 }
@@ -25,8 +28,11 @@ double Parameters::getValue(Name name) {
 void Parameters::addParameter(Name name, double value) {
 	map<Name, double>::iterator it = _params.find(name);
     if ( it != _params.end() ) {
-        cerr << "[ERROR] Cannot addParameter " << name.getString() << " because it already exists !" << endl;
-        return;
+        string error("[ERROR] Cannot addParameter ");
+        error += name.getString();
+        error += " because it already exists !";
+        throw OpenChamsException(error);
+        //return;
     }
     _params[name] = value;
 }
diff --git a/vlsisapd/openChams/Parameters.h b/vlsisapd/openChams/Parameters.h
index 544af749..d6d2a698 100644
--- a/vlsisapd/openChams/Parameters.h
+++ b/vlsisapd/openChams/Parameters.h
@@ -11,7 +11,6 @@
 #define __OPENCHAMS_PARAMETERS_H__
 
 #include <map>
-using namespace std;
 
 #include "Name.h"
 
@@ -25,16 +24,18 @@ public:
     
     // pour parcourir la map :
     inline bool isEmpty();
-    inline map<Name, double>::iterator getFirstIt();
-    inline map<Name, double>::iterator getLastIt();
+    //inline map<Name, double>::iterator getFirstIt();
+    //inline map<Name, double>::iterator getLastIt();
+    inline const std::map<Name, double>& getValues();
     
 private:
-    map<Name, double> _params;
+    std::map<Name, double> _params;
 };
     
 inline bool Parameters::isEmpty() { return (_params.size() == 0)? true : false; }
-inline map<Name, double>::iterator Parameters::getFirstIt() { return _params.begin(); }
-inline map<Name, double>::iterator Parameters::getLastIt()  { return _params.end(); }
+//inline map<Name, double>::iterator Parameters::getFirstIt() { return _params.begin(); }
+//inline map<Name, double>::iterator Parameters::getLastIt()  { return _params.end(); }
+inline const std::map<Name, double>& Parameters::getValues() { return _params; };
 
 } // namespace
 #endif
diff --git a/vlsisapd/openChams/Schematic.cpp b/vlsisapd/openChams/Schematic.cpp
new file mode 100644
index 00000000..ce938b2d
--- /dev/null
+++ b/vlsisapd/openChams/Schematic.cpp
@@ -0,0 +1,35 @@
+/*
+ *  SchematicInfos.cpp
+ *  openChams
+ *
+ *  Created by damien dupuis on 22/01/10.
+ *  Copyright 2010 UPMC / LIP6. All rights reserved.
+ *
+ */
+
+using namespace std;
+
+#include "Schematic.h"
+#include "OpenChamsException.h"
+
+namespace OpenChams {
+Schematic::Schematic(Circuit* circuit, double zoom) 
+    : _circuit(circuit)
+    , _zoom(zoom) {}
+    
+void Schematic::addInstance(Name instanceName, double x, double y, Name sym) {
+    map<Name, Schematic::Infos*>::iterator it = _instances.find(instanceName);
+    if (it != _instances.end()) {
+        string error("[ERROR] Cannot set same instance twice in 'schematic' (");
+        error += instanceName.getString();
+        error += ").";
+        throw OpenChamsException(error);
+    }
+    _instances[instanceName] = new Schematic::Infos(x, y, sym);
+}
+
+Schematic::Infos::Infos(double x, double y, Name sym)
+    : _x(x)
+    , _y(y)
+    , _sym(sym) {}
+} // namespace
diff --git a/vlsisapd/openChams/Schematic.h b/vlsisapd/openChams/Schematic.h
new file mode 100644
index 00000000..eced02dd
--- /dev/null
+++ b/vlsisapd/openChams/Schematic.h
@@ -0,0 +1,58 @@
+/*
+ *  SchematicInfos.h
+ *  openChams
+ *
+ *  Created by damien dupuis on 22/01/10.
+ *  Copyright 2010 UPMC / LIP6. All rights reserved.
+ *
+ */
+
+#ifndef __OPENCHAMS_SCHEMATIC_H__
+#define __OPENCHAMS_SCHEMATIC_H__
+
+#include <map>
+
+#include "Name.h"
+
+namespace OpenChams {
+class Circuit;
+class Schematic {
+	public:
+    class Infos {
+    	public:
+        Infos(double x, double y, Name sym);
+        
+    	inline double getX();
+        inline double getY();
+        inline Name   getSymetry();
+        
+	    private:
+        double _x;
+        double _y;
+        Name   _sym;
+    };
+	public:
+    Schematic(Circuit*, double);
+        
+    void addInstance(Name instanceName, double x, double y, Name sym );
+        
+    inline double getZoom();
+    inline bool   hasNoInstances();
+    inline const std::map<Name, Infos*>& getInstances();
+        
+    private:
+    Circuit* _circuit;
+    double   _zoom;
+    std::map<Name, Infos*> _instances;
+};
+
+inline double Schematic::getZoom()        { return _zoom; };
+inline bool   Schematic::hasNoInstances() { return (_instances.size() == 0) ? true : false; };
+inline const std::map<Name, Schematic::Infos*>& Schematic::getInstances() { return _instances; };    
+    
+inline double Schematic::Infos::getX()       { return _x; };
+inline double Schematic::Infos::getY()       { return _y; };
+inline Name   Schematic::Infos::getSymetry() { return _sym; };
+    
+} // namespace
+#endif
\ No newline at end of file