Enabling user-specified required times in 'map'.

10 files changed, 200 insertions, 30 deletions

diff --git a/src/base/abc/abc.h b/src/base/abc/abc.h
index 99cf605a..272e4fb6 100644
--- a/src/base/abc/abc.h
+++ b/src/base/abc/abc.h
@@ -867,12 +867,13 @@ extern ABC_DLL void               Abc_NtkTimeSetDefaultArrival( Abc_Ntk_t * pNtk
 extern ABC_DLL void               Abc_NtkTimeSetDefaultRequired( Abc_Ntk_t * pNtk, float Rise, float Fall );
 extern ABC_DLL void               Abc_NtkTimeSetArrival( Abc_Ntk_t * pNtk, int ObjId, float Rise, float Fall );
 extern ABC_DLL void               Abc_NtkTimeSetRequired( Abc_Ntk_t * pNtk, int ObjId, float Rise, float Fall );
-extern ABC_DLL void               Abc_NtkTimeInitialize( Abc_Ntk_t * pNtk );
+extern ABC_DLL void               Abc_NtkTimeInitialize( Abc_Ntk_t * pNtk, Abc_Ntk_t * pNtkOld );
 extern ABC_DLL void               Abc_ManTimeStop( Abc_ManTime_t * p );
 extern ABC_DLL void               Abc_ManTimeDup( Abc_Ntk_t * pNtkOld, Abc_Ntk_t * pNtkNew );
 extern ABC_DLL void               Abc_NtkSetNodeLevelsArrival( Abc_Ntk_t * pNtk );
 extern ABC_DLL float *            Abc_NtkGetCiArrivalFloats( Abc_Ntk_t * pNtk );
 extern ABC_DLL Abc_Time_t *       Abc_NtkGetCiArrivalTimes( Abc_Ntk_t * pNtk );
+extern ABC_DLL Abc_Time_t *       Abc_NtkGetCoRequiredTimes( Abc_Ntk_t * pNtk );
 extern ABC_DLL float              Abc_NtkDelayTrace( Abc_Ntk_t * pNtk );
 extern ABC_DLL int                Abc_ObjLevelNew( Abc_Obj_t * pObj );
 extern ABC_DLL int                Abc_ObjReverseLevelNew( Abc_Obj_t * pObj );
diff --git a/src/base/abc/abcNtk.c b/src/base/abc/abcNtk.c
index 3840fdfc..42036f4b 100644
--- a/src/base/abc/abcNtk.c
+++ b/src/base/abc/abcNtk.c
@@ -226,6 +226,9 @@ void Abc_NtkFinalize( Abc_Ntk_t * pNtk, Abc_Ntk_t * pNtkNew )
         pDriverNew = Abc_ObjNotCond(pDriver->pCopy, Abc_ObjFaninC0(pObj));
         Abc_ObjAddFanin( pObj->pCopy, pDriverNew );
     }
+    // duplicate timing manager
+    if ( pNtk->pManTime )
+        Abc_NtkTimeInitialize( pNtkNew, pNtk );
 }
 
 /**Function*************************************************************
@@ -378,6 +381,10 @@ Abc_Ntk_t * Abc_NtkDup( Abc_Ntk_t * pNtk )
         pNtkNew->pExdc = Abc_NtkDup( pNtk->pExdc );
     if ( pNtk->pExcare )
         pNtkNew->pExcare = Abc_NtkDup( (Abc_Ntk_t *)pNtk->pExcare );
+    // duplicate timing manager
+    if ( pNtk->pManTime )
+        Abc_NtkTimeInitialize( pNtkNew, pNtk );
+    // check correctness
     if ( !Abc_NtkCheck( pNtkNew ) )
         fprintf( stdout, "Abc_NtkDup(): Network check has failed.\n" );
     pNtk->pCopy = pNtkNew;
diff --git a/src/base/abci/abcMap.c b/src/base/abci/abcMap.c
index eeeaf15f..723e5688 100644
--- a/src/base/abci/abcMap.c
+++ b/src/base/abci/abcMap.c
@@ -163,6 +163,7 @@ Map_Man_t * Abc_NtkToMap( Abc_Ntk_t * pNtk, double DelayTarget, int fRecovery, f
     Map_ManSetOutputNames( pMan, Abc_NtkCollectCioNames(pNtk, 1) );
     Map_ManSetDelayTarget( pMan, (float)DelayTarget );
     Map_ManSetInputArrivals( pMan, (Map_Time_t *)Abc_NtkGetCiArrivalTimes(pNtk) );
+    Map_ManSetOutputRequireds( pMan, (Map_Time_t *)Abc_NtkGetCoRequiredTimes(pNtk) );
 
     // create PIs and remember them in the old nodes
     Abc_NtkCleanCopy( pNtk );
diff --git a/src/base/abci/abcTiming.c b/src/base/abci/abcTiming.c
index d8334e9d..a9b50563 100644
--- a/src/base/abci/abcTiming.c
+++ b/src/base/abci/abcTiming.c
@@ -40,7 +40,6 @@ struct Abc_ManTime_t_
 // static functions
 static Abc_ManTime_t *     Abc_ManTimeStart();
 static void                Abc_ManTimeExpand( Abc_ManTime_t * p, int nSize, int fProgressive );
-void                       Abc_NtkTimePrepare( Abc_Ntk_t * pNtk );
 
 void                       Abc_NodeDelayTraceArrival( Abc_Obj_t * pNode );
 
@@ -139,7 +138,7 @@ void Abc_NtkTimeSetDefaultArrival( Abc_Ntk_t * pNtk, float Rise, float Fall )
         pNtk->pManTime = Abc_ManTimeStart();
     pNtk->pManTime->tArrDef.Rise  = Rise;
     pNtk->pManTime->tArrDef.Fall  = Fall;
-    pNtk->pManTime->tArrDef.Worst = Abc_MaxInt( Rise, Fall );
+    pNtk->pManTime->tArrDef.Worst = Abc_MaxFloat( Rise, Fall );
 }
 
 /**Function*************************************************************
@@ -161,7 +160,7 @@ void Abc_NtkTimeSetDefaultRequired( Abc_Ntk_t * pNtk, float Rise, float Fall )
         pNtk->pManTime = Abc_ManTimeStart();
     pNtk->pManTime->tReqDef.Rise  = Rise;
     pNtk->pManTime->tReqDef.Fall  = Fall;
-    pNtk->pManTime->tReqDef.Worst = Abc_MaxInt( Rise, Fall );
+    pNtk->pManTime->tReqDef.Worst = Abc_MaxFloat( Rise, Fall );
 }
 
 /**Function*************************************************************
@@ -189,7 +188,7 @@ void Abc_NtkTimeSetArrival( Abc_Ntk_t * pNtk, int ObjId, float Rise, float Fall
     pTime = (Abc_Time_t *)vTimes->pArray[ObjId];
     pTime->Rise  = Rise;
     pTime->Fall  = Fall;
-    pTime->Worst = Abc_MaxInt( Rise, Fall );
+    pTime->Worst = Abc_MaxFloat( Rise, Fall );
 }
 
 /**Function*************************************************************
@@ -217,7 +216,7 @@ void Abc_NtkTimeSetRequired( Abc_Ntk_t * pNtk, int ObjId, float Rise, float Fall
     pTime = (Abc_Time_t *)vTimes->pArray[ObjId];
     pTime->Rise  = Rise;
     pTime->Fall  = Fall;
-    pTime->Worst = Abc_MaxInt( Rise, Fall );
+    pTime->Worst = Abc_MaxFloat( Rise, Fall );
 }
 
 /**Function*************************************************************
@@ -231,14 +230,23 @@ void Abc_NtkTimeSetRequired( Abc_Ntk_t * pNtk, int ObjId, float Rise, float Fall
   SeeAlso     []
 
 ***********************************************************************/
-void Abc_NtkTimeInitialize( Abc_Ntk_t * pNtk )
+void Abc_NtkTimeInitialize( Abc_Ntk_t * pNtk, Abc_Ntk_t * pNtkOld )
 {
     Abc_Obj_t * pObj;
     Abc_Time_t ** ppTimes, * pTime;
     int i;
+    assert( pNtkOld == NULL || pNtkOld->pManTime != NULL );
+    assert( pNtkOld == NULL || Abc_NtkPiNum(pNtk) == Abc_NtkPiNum(pNtkOld) );
+    assert( pNtkOld == NULL || Abc_NtkPoNum(pNtk) == Abc_NtkPoNum(pNtkOld) );
     if ( pNtk->pManTime == NULL )
         return;
     Abc_ManTimeExpand( pNtk->pManTime, Abc_NtkObjNumMax(pNtk), 0 );
+    // set global defaults
+    if ( pNtkOld )
+    {
+        pNtk->pManTime->tArrDef = pNtkOld->pManTime->tArrDef;
+        pNtk->pManTime->tReqDef = pNtkOld->pManTime->tReqDef;
+    }
     // set the default timing
     ppTimes = (Abc_Time_t **)pNtk->pManTime->vArrs->pArray;
     Abc_NtkForEachPi( pNtk, pObj, i )
@@ -246,7 +254,7 @@ void Abc_NtkTimeInitialize( Abc_Ntk_t * pNtk )
         pTime = ppTimes[pObj->Id];
         if ( pTime->Worst != -ABC_INFINITY )
             continue;
-        *pTime = pNtk->pManTime->tArrDef;
+        *pTime = pNtkOld ? *Abc_NodeReadArrival(Abc_NtkPi(pNtkOld, i)) : pNtk->pManTime->tArrDef;
     }
     // set the default timing
     ppTimes = (Abc_Time_t **)pNtk->pManTime->vReqs->pArray;
@@ -255,7 +263,7 @@ void Abc_NtkTimeInitialize( Abc_Ntk_t * pNtk )
         pTime = ppTimes[pObj->Id];
         if ( pTime->Worst != -ABC_INFINITY )
             continue;
-        *pTime = pNtk->pManTime->tReqDef;
+        *pTime = pNtkOld ? *Abc_NodeReadRequired(Abc_NtkPo(pNtkOld, i)) : pNtk->pManTime->tReqDef;
     }
     // set the 0 arrival times for latch outputs and constant nodes
     ppTimes = (Abc_Time_t **)pNtk->pManTime->vArrs->pArray;
@@ -286,7 +294,7 @@ void Abc_NtkTimePrepare( Abc_Ntk_t * pNtk )
     if ( pNtk->pManTime == NULL )
     {
         pNtk->pManTime = Abc_ManTimeStart();
-        Abc_NtkTimeInitialize( pNtk );
+        Abc_NtkTimeInitialize( pNtk, NULL );
         return;
     }
     // if timing manager is given, expand it if necessary
@@ -304,6 +312,17 @@ void Abc_NtkTimePrepare( Abc_Ntk_t * pNtk )
         pTime->Fall = pTime->Rise = pTime->Worst = -ABC_INFINITY;
     }
     // clean required except for POs
+    ppTimes = (Abc_Time_t **)pNtk->pManTime->vReqs->pArray;
+    Abc_NtkForEachNode( pNtk, pObj, i )
+    {
+        pTime = ppTimes[pObj->Id];
+        pTime->Fall = pTime->Rise = pTime->Worst = -ABC_INFINITY;
+    }
+    Abc_NtkForEachPi( pNtk, pObj, i )
+    {
+        pTime = ppTimes[pObj->Id];
+        pTime->Fall = pTime->Rise = pTime->Worst = -ABC_INFINITY;
+    }
 }
 
 
@@ -499,8 +518,7 @@ Abc_Time_t * Abc_NtkGetCiArrivalTimes( Abc_Ntk_t * pNtk )
     Abc_Time_t * p;
     Abc_Obj_t * pNode;
     int i;
-    p = ABC_ALLOC( Abc_Time_t, Abc_NtkCiNum(pNtk) );
-    memset( p, 0, sizeof(Abc_Time_t) * Abc_NtkCiNum(pNtk) );
+    p = ABC_CALLOC( Abc_Time_t, Abc_NtkCiNum(pNtk) );
     if ( pNtk->pManTime == NULL )
         return p;
     // set the PI arrival times
@@ -509,6 +527,31 @@ Abc_Time_t * Abc_NtkGetCiArrivalTimes( Abc_Ntk_t * pNtk )
     return p;
 }
 
+/**Function*************************************************************
+
+  Synopsis    [Sets the CI node levels according to the arrival info.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+Abc_Time_t * Abc_NtkGetCoRequiredTimes( Abc_Ntk_t * pNtk )
+{
+    Abc_Time_t * p;
+    Abc_Obj_t * pNode;
+    int i;
+    p = ABC_CALLOC( Abc_Time_t, Abc_NtkCoNum(pNtk) );
+    if ( pNtk->pManTime == NULL )
+        return p;
+    // set the PO required times
+    Abc_NtkForEachPo( pNtk, pNode, i )
+        p[i] = *Abc_NodeRequired(pNode);
+    return p;
+}
+
 
 /**Function*************************************************************
 
@@ -526,8 +569,7 @@ float * Abc_NtkGetCiArrivalFloats( Abc_Ntk_t * pNtk )
     float * p;
     Abc_Obj_t * pNode;
     int i;
-    p = ABC_ALLOC( float, Abc_NtkCiNum(pNtk) );
-    memset( p, 0, sizeof(float) * Abc_NtkCiNum(pNtk) );
+    p = ABC_CALLOC( float, Abc_NtkCiNum(pNtk) );
     if ( pNtk->pManTime == NULL )
         return p;
     // set the PI arrival times
@@ -625,7 +667,7 @@ void Abc_NodeDelayTraceArrival( Abc_Obj_t * pNode )
         }
         pPin = Mio_PinReadNext(pPin);
     }
-    pTimeOut->Worst = Abc_MaxInt( pTimeOut->Rise, pTimeOut->Fall );
+    pTimeOut->Worst = Abc_MaxFloat( pTimeOut->Rise, pTimeOut->Fall );
 }
 
 
@@ -647,7 +689,7 @@ int Abc_ObjLevelNew( Abc_Obj_t * pObj )
     Abc_Obj_t * pFanin;
     int i, Level = 0;
     Abc_ObjForEachFanin( pObj, pFanin, i )
-        Level = Abc_MaxInt( Level, Abc_ObjLevel(pFanin) );
+        Level = Abc_MaxFloat( Level, Abc_ObjLevel(pFanin) );
     return Level + 1;
 }
 
@@ -669,7 +711,7 @@ int Abc_ObjReverseLevelNew( Abc_Obj_t * pObj )
     Abc_ObjForEachFanout( pObj, pFanout, i )
     {
         LevelCur = Abc_ObjReverseLevel( pFanout );
-        Level = Abc_MaxInt( Level, LevelCur );
+        Level = Abc_MaxFloat( Level, LevelCur );
     }
     return Level + 1;
 }
@@ -827,7 +869,7 @@ void Abc_NtkUpdateLevel( Abc_Obj_t * pObjNew, Vec_Vec_t * vLevels )
                 assert( Abc_ObjLevel(pFanout) >= Lev );
                 Vec_VecPush( vLevels, Abc_ObjLevel(pFanout), pFanout );
 //                Counter++;
-//                CounterMax = Abc_MaxInt( CounterMax, Counter );
+//                CounterMax = Abc_MaxFloat( CounterMax, Counter );
                 pFanout->fMarkA = 1;
             }
         }
diff --git a/src/base/io/ioReadBlif.c b/src/base/io/ioReadBlif.c
index faf0f53e..eb919210 100644
--- a/src/base/io/ioReadBlif.c
+++ b/src/base/io/ioReadBlif.c
@@ -64,7 +64,9 @@ static int Io_ReadBlifNetworkNames( Io_ReadBlif_t * p, Vec_Ptr_t ** pvTokens );
 static int Io_ReadBlifNetworkGate( Io_ReadBlif_t * p, Vec_Ptr_t * vTokens );
 static int Io_ReadBlifNetworkSubcircuit( Io_ReadBlif_t * p, Vec_Ptr_t * vTokens );
 static int Io_ReadBlifNetworkInputArrival( Io_ReadBlif_t * p, Vec_Ptr_t * vTokens );
+static int Io_ReadBlifNetworkOutputRequired( Io_ReadBlif_t * p, Vec_Ptr_t * vTokens );
 static int Io_ReadBlifNetworkDefaultInputArrival( Io_ReadBlif_t * p, Vec_Ptr_t * vTokens );
+static int Io_ReadBlifNetworkDefaultOutputRequired( Io_ReadBlif_t * p, Vec_Ptr_t * vTokens );
 static int Io_ReadBlifNetworkConnectBoxes( Io_ReadBlif_t * p, Abc_Ntk_t * pNtkMaster );
 
 ////////////////////////////////////////////////////////////////////////
@@ -100,7 +102,7 @@ Abc_Ntk_t * Io_ReadBlif( char * pFileName, int fCheck )
         return NULL;
     }
     pNtk->pSpec = Extra_UtilStrsav( pFileName );
-    Abc_NtkTimeInitialize( pNtk );
+    Abc_NtkTimeInitialize( pNtk, NULL );
     Io_ReadBlifFree( p );
 
     // make sure that everything is okay with the network structure
@@ -267,8 +269,12 @@ Abc_Ntk_t * Io_ReadBlifNetworkOne( Io_ReadBlif_t * p )
             fStatus = Io_ReadBlifNetworkOutputs( p, p->vTokens );
         else if ( !strcmp( pDirective, ".input_arrival" ) )
             fStatus = Io_ReadBlifNetworkInputArrival( p, p->vTokens );
+        else if ( !strcmp( pDirective, ".output_required" ) )
+            fStatus = Io_ReadBlifNetworkOutputRequired( p, p->vTokens );
         else if ( !strcmp( pDirective, ".default_input_arrival" ) )
             fStatus = Io_ReadBlifNetworkDefaultInputArrival( p, p->vTokens );
+        else if ( !strcmp( pDirective, ".default_output_required" ) )
+            fStatus = Io_ReadBlifNetworkDefaultOutputRequired( p, p->vTokens );
 //        else if ( !strcmp( pDirective, ".subckt" ) )
 //            fStatus = Io_ReadBlifNetworkSubcircuit( p, p->vTokens );
         else if ( !strcmp( pDirective, ".exdc" ) )
@@ -782,6 +788,54 @@ int Io_ReadBlifNetworkInputArrival( Io_ReadBlif_t * p, Vec_Ptr_t * vTokens )
   SeeAlso     []
 
 ***********************************************************************/
+int Io_ReadBlifNetworkOutputRequired( Io_ReadBlif_t * p, Vec_Ptr_t * vTokens )
+{
+    Abc_Obj_t * pNet;
+    char * pFoo1, * pFoo2;
+    double TimeRise, TimeFall;
+ 
+    // make sure this is indeed the .inputs line
+    assert( strncmp( (char *)vTokens->pArray[0], ".output_required", 16 ) == 0 );
+    if ( vTokens->nSize != 4 )
+    {
+        p->LineCur = Extra_FileReaderGetLineNumber(p->pReader, 0);
+        sprintf( p->sError, "Wrong number of arguments on .output_required line." );
+        Io_ReadBlifPrintErrorMessage( p );
+        return 1;
+    }
+    pNet = Abc_NtkFindNet( p->pNtkCur, (char *)vTokens->pArray[1] );
+    if ( pNet == NULL )
+    {
+        p->LineCur = Extra_FileReaderGetLineNumber(p->pReader, 0);
+        sprintf( p->sError, "Cannot find object corresponding to %s on .output_required line.", (char*)vTokens->pArray[1] );
+        Io_ReadBlifPrintErrorMessage( p );
+        return 1;
+    }
+    TimeRise = strtod( (char *)vTokens->pArray[2], &pFoo1 );
+    TimeFall = strtod( (char *)vTokens->pArray[3], &pFoo2 );
+    if ( *pFoo1 != '\0' || *pFoo2 != '\0' )
+    {
+        p->LineCur = Extra_FileReaderGetLineNumber(p->pReader, 0);
+        sprintf( p->sError, "Bad value (%s %s) for rise or fall time on .output_required line.", (char*)vTokens->pArray[2], (char*)vTokens->pArray[3] );
+        Io_ReadBlifPrintErrorMessage( p );
+        return 1;
+    }
+    // set the arrival time
+    Abc_NtkTimeSetRequired( p->pNtkCur, Abc_ObjFanout0(pNet)->Id, (float)TimeRise, (float)TimeFall );
+    return 0;
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
 int Io_ReadBlifNetworkDefaultInputArrival( Io_ReadBlif_t * p, Vec_Ptr_t * vTokens )
 {
     char * pFoo1, * pFoo2;
@@ -812,6 +866,45 @@ int Io_ReadBlifNetworkDefaultInputArrival( Io_ReadBlif_t * p, Vec_Ptr_t * vToken
 
 /**Function*************************************************************
 
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Io_ReadBlifNetworkDefaultOutputRequired( Io_ReadBlif_t * p, Vec_Ptr_t * vTokens )
+{
+    char * pFoo1, * pFoo2;
+    double TimeRise, TimeFall;
+
+    // make sure this is indeed the .inputs line
+    assert( strncmp( (char *)vTokens->pArray[0], ".default_output_required", 25 ) == 0 );
+    if ( vTokens->nSize != 3 )
+    {
+        p->LineCur = Extra_FileReaderGetLineNumber(p->pReader, 0);
+        sprintf( p->sError, "Wrong number of arguments on .default_output_required line." );
+        Io_ReadBlifPrintErrorMessage( p );
+        return 1;
+    }
+    TimeRise = strtod( (char *)vTokens->pArray[1], &pFoo1 );
+    TimeFall = strtod( (char *)vTokens->pArray[2], &pFoo2 );
+    if ( *pFoo1 != '\0' || *pFoo2 != '\0' )
+    {
+        p->LineCur = Extra_FileReaderGetLineNumber(p->pReader, 0);
+        sprintf( p->sError, "Bad value (%s %s) for rise or fall time on .default_output_required line.", (char*)vTokens->pArray[1], (char*)vTokens->pArray[2] );
+        Io_ReadBlifPrintErrorMessage( p );
+        return 1;
+    }
+    // set the arrival time
+    Abc_NtkTimeSetDefaultRequired( p->pNtkCur, (float)TimeRise, (float)TimeFall );
+    return 0;
+}
+
+/**Function*************************************************************
+
   Synopsis    [Prints the error message including the file name and line number.]
 
   Description []
diff --git a/src/base/io/ioWriteBlif.c b/src/base/io/ioWriteBlif.c
index fe4266b0..327e16e1 100644
--- a/src/base/io/ioWriteBlif.c
+++ b/src/base/io/ioWriteBlif.c
@@ -589,6 +589,8 @@ void Io_WriteTimingInfo( FILE * pFile, Abc_Ntk_t * pNtk )
     if ( pNtk->pManTime == NULL )
         return;
 
+    fprintf( pFile, "\n" );
+
     pTimeDef = Abc_NtkReadDefaultArrival( pNtk );
     fprintf( pFile, ".default_input_arrival %g %g\n", pTimeDef->Rise, pTimeDef->Fall );
     Abc_NtkForEachPi( pNtk, pNode, i )
@@ -596,9 +598,18 @@ void Io_WriteTimingInfo( FILE * pFile, Abc_Ntk_t * pNtk )
         pTime = Abc_NodeReadArrival(pNode);
         if ( pTime->Rise == pTimeDef->Rise && pTime->Fall == pTimeDef->Fall )
             continue;
-//        fprintf( pFile, ".input_arrival %s %g %g\n", Abc_ObjName(pNode), pTime->Rise, pTime->Fall );
         fprintf( pFile, ".input_arrival %s %g %g\n", Abc_ObjName(Abc_ObjFanout0(pNode)), pTime->Rise, pTime->Fall );
     }
+
+    pTimeDef = Abc_NtkReadDefaultRequired( pNtk );
+    fprintf( pFile, ".default_output_required %g %g\n", pTimeDef->Rise, pTimeDef->Fall );
+    Abc_NtkForEachPo( pNtk, pNode, i )
+    {
+        pTime = Abc_NodeReadRequired(pNode);
+        if ( pTime->Rise == pTimeDef->Rise && pTime->Fall == pTimeDef->Fall )
+            continue;
+        fprintf( pFile, ".output_required %s %g %g\n", Abc_ObjName(Abc_ObjFanin0(pNode)), pTime->Rise, pTime->Fall );
+    }
 }
 
 
diff --git a/src/map/mapper/mapper.h b/src/map/mapper/mapper.h
index 3fd5fd9e..29bc98ef 100644
--- a/src/map/mapper/mapper.h
+++ b/src/map/mapper/mapper.h
@@ -97,6 +97,7 @@ extern void            Map_ManSetOutputNames( Map_Man_t * p, char ** ppNames );
 extern void            Map_ManSetAreaRecovery( Map_Man_t * p, int fAreaRecovery );
 extern void            Map_ManSetDelayTarget( Map_Man_t * p, float DelayTarget );
 extern void            Map_ManSetInputArrivals( Map_Man_t * p, Map_Time_t * pArrivals );
+extern void            Map_ManSetOutputRequireds( Map_Man_t * p, Map_Time_t * pArrivals );
 extern void            Map_ManSetObeyFanoutLimits( Map_Man_t * p, int  fObeyFanoutLimits );              
 extern void            Map_ManSetNumIterations( Map_Man_t * p, int nNumIterations );
 extern int             Map_ManReadPass( Map_Man_t * p );
diff --git a/src/map/mapper/mapperCreate.c b/src/map/mapper/mapperCreate.c
index 73ccdb19..2b1663a4 100644
--- a/src/map/mapper/mapperCreate.c
+++ b/src/map/mapper/mapperCreate.c
@@ -52,26 +52,28 @@ int             Map_ManReadOutputNum( Map_Man_t * p )                   { return
 Map_Node_t **   Map_ManReadInputs ( Map_Man_t * p )                     { return p->pInputs;    }
 Map_Node_t **   Map_ManReadOutputs( Map_Man_t * p )                     { return p->pOutputs;   }
 Map_Node_t *    Map_ManReadConst1 ( Map_Man_t * p )                     { return p->pConst1;    }
-Map_Time_t *    Map_ManReadInputArrivals( Map_Man_t * p )               { return p->pInputArrivals;}
+Map_Time_t *    Map_ManReadInputArrivals( Map_Man_t * p )               { return p->pInputArrivals; }
+Map_Time_t *    Map_ManReadOutputRequireds( Map_Man_t * p )             { return p->pOutputRequireds; }
 Mio_Library_t * Map_ManReadGenLib ( Map_Man_t * p )                     { return p->pSuperLib->pGenlib; }
 int             Map_ManReadVerbose( Map_Man_t * p )                     { return p->fVerbose;   }
 float           Map_ManReadAreaFinal( Map_Man_t * p )                   { return p->AreaFinal;  }
-float           Map_ManReadRequiredGlo( Map_Man_t * p )                 { return p->fRequiredGlo;  }
+float           Map_ManReadRequiredGlo( Map_Man_t * p )                 { return p->fRequiredGlo; }
 void            Map_ManSetTimeToMap( Map_Man_t * p, int Time )          { p->timeToMap = Time;  }
 void            Map_ManSetTimeToNet( Map_Man_t * p, int Time )          { p->timeToNet = Time;  }
 void            Map_ManSetTimeSweep( Map_Man_t * p, int Time )          { p->timeSweep = Time;  }
 void            Map_ManSetTimeTotal( Map_Man_t * p, int Time )          { p->timeTotal = Time;  }
-void            Map_ManSetOutputNames( Map_Man_t * p, char ** ppNames ) { p->ppOutputNames = ppNames; }
+void            Map_ManSetOutputNames( Map_Man_t * p, char ** ppNames ) { p->ppOutputNames = ppNames;}
 void            Map_ManSetAreaRecovery( Map_Man_t * p, int fAreaRecovery ) { p->fAreaRecovery = fAreaRecovery;}
 void            Map_ManSetDelayTarget( Map_Man_t * p, float DelayTarget ) { p->DelayTarget = DelayTarget;}
-void            Map_ManSetInputArrivals( Map_Man_t * p, Map_Time_t * pArrivals ) { p->pInputArrivals = pArrivals;}
+void            Map_ManSetInputArrivals( Map_Man_t * p, Map_Time_t * pArrivals )     { p->pInputArrivals = pArrivals;    }
+void            Map_ManSetOutputRequireds( Map_Man_t * p, Map_Time_t * pRequireds )  { p->pOutputRequireds = pRequireds; }
 void            Map_ManSetObeyFanoutLimits( Map_Man_t * p, int  fObeyFanoutLimits )  { p->fObeyFanoutLimits = fObeyFanoutLimits;     }
 void            Map_ManSetNumIterations( Map_Man_t * p, int nIterations )            { p->nIterations = nIterations;     }
-int             Map_ManReadFanoutViolations( Map_Man_t * p )            { return p->nFanoutViolations; }  
-void            Map_ManSetFanoutViolations( Map_Man_t * p, int nVio )   { p->nFanoutViolations = nVio; }  
+int             Map_ManReadFanoutViolations( Map_Man_t * p )            { return p->nFanoutViolations;   }  
+void            Map_ManSetFanoutViolations( Map_Man_t * p, int nVio )   { p->nFanoutViolations = nVio;   }  
 void            Map_ManSetChoiceNodeNum( Map_Man_t * p, int nChoiceNodes ) { p->nChoiceNodes = nChoiceNodes; }  
-void            Map_ManSetChoiceNum( Map_Man_t * p, int nChoices )         { p->nChoices = nChoices; }   
-void            Map_ManSetVerbose( Map_Man_t * p, int fVerbose )           { p->fVerbose = fVerbose; }   
+void            Map_ManSetChoiceNum( Map_Man_t * p, int nChoices )         { p->nChoices = nChoices;     }   
+void            Map_ManSetVerbose( Map_Man_t * p, int fVerbose )           { p->fVerbose = fVerbose;     }   
 void            Map_ManSetSwitching( Map_Man_t * p, int fSwitching )       { p->fSwitching = fSwitching; }   
 
 /**Function*************************************************************
@@ -267,6 +269,7 @@ void Map_ManFree( Map_Man_t * p )
     Extra_MmFixedStop( p->mmNodes );
     Extra_MmFixedStop( p->mmCuts );
     ABC_FREE( p->pInputArrivals );
+    ABC_FREE( p->pOutputRequireds );
     ABC_FREE( p->pInputs );
     ABC_FREE( p->pOutputs );
     ABC_FREE( p->pBins );
diff --git a/src/map/mapper/mapperInt.h b/src/map/mapper/mapperInt.h
index 08a27e68..8d1e3fb7 100644
--- a/src/map/mapper/mapperInt.h
+++ b/src/map/mapper/mapperInt.h
@@ -106,6 +106,7 @@ struct Map_ManStruct_t_
     // info about the original circuit
     char **             ppOutputNames; // the primary output names
     Map_Time_t *        pInputArrivals;// the PI arrival times
+    Map_Time_t *        pOutputRequireds;// the PI arrival times
 
     // mapping parameters
     int                 nVarsMax;      // the max number of variables
diff --git a/src/map/mapper/mapperTime.c b/src/map/mapper/mapperTime.c
index d12b607a..162e6f9a 100644
--- a/src/map/mapper/mapperTime.c
+++ b/src/map/mapper/mapperTime.c
@@ -231,7 +231,7 @@ void Map_TimeComputeRequiredGlobal( Map_Man_t * p )
 ***********************************************************************/
 void Map_TimeComputeRequired( Map_Man_t * p, float fRequired )
 {
-    Map_Time_t * ptTime;
+    Map_Time_t * ptTime, * ptTimeA;
     int fPhase, i;
 
     // clean the required times
@@ -250,7 +250,17 @@ void Map_TimeComputeRequired( Map_Man_t * p, float fRequired )
     {
         fPhase  = !Map_IsComplement(p->pOutputs[i]);
         ptTime  =  Map_Regular(p->pOutputs[i])->tRequired + fPhase;
-        ptTime->Rise = ptTime->Fall = ptTime->Worst = fRequired;
+        ptTimeA =  Map_Regular(p->pOutputs[i])->tArrival + fPhase;
+
+        // if external required time can be achieved, use it
+        if ( p->pOutputRequireds && p->pOutputRequireds[i].Worst > 0 && ptTimeA->Worst <= p->pOutputRequireds[i].Worst && p->pOutputRequireds[i].Worst <= fRequired )
+            ptTime->Rise = ptTime->Fall = ptTime->Worst = p->pOutputRequireds[i].Worst;
+        // if external required cannot be achieved, set the earliest possible arrival time
+        else if ( p->pOutputRequireds && p->pOutputRequireds[i].Worst > 0 && ptTimeA->Worst > p->pOutputRequireds[i].Worst )
+            ptTime->Rise = ptTime->Fall = ptTime->Worst = ptTimeA->Worst;
+        // otherwise, set the global required time
+        else
+            ptTime->Rise = ptTime->Fall = ptTime->Worst = fRequired;
     }
 
     // sorts the nodes in the decreasing order of levels