diff --git a/cumulus/src/CMakeLists.txt b/cumulus/src/CMakeLists.txt
index 280da117..344f5556 100644
--- a/cumulus/src/CMakeLists.txt
+++ b/cumulus/src/CMakeLists.txt
@@ -59,6 +59,7 @@
                                        ${CMAKE_CURRENT_SOURCE_DIR}/plugins/alpha/block/hfns2.py
                                        ${CMAKE_CURRENT_SOURCE_DIR}/plugins/alpha/block/hfns3.py
                                        ${CMAKE_CURRENT_SOURCE_DIR}/plugins/alpha/block/hfns4.py
+                                       ${CMAKE_CURRENT_SOURCE_DIR}/plugins/alpha/block/matrix.py
                   )
               set ( pyPluginAlphaC2C   ${CMAKE_CURRENT_SOURCE_DIR}/plugins/alpha/core2chip/__init__.py
                                        ${CMAKE_CURRENT_SOURCE_DIR}/plugins/alpha/core2chip/core2chip.py
diff --git a/cumulus/src/plugins/alpha/block/matrix.py b/cumulus/src/plugins/alpha/block/matrix.py
new file mode 100644
index 00000000..1eb537ca
--- /dev/null
+++ b/cumulus/src/plugins/alpha/block/matrix.py
@@ -0,0 +1,167 @@
+
+# This file is part of the Coriolis Software.
+# Copyright (c) SU 2021-2021, All Rights Reserved
+#
+# +-----------------------------------------------------------------+
+# |                   C O R I O L I S                               |
+# |      C u m u l u s  -  P y t h o n   T o o l s                  |
+# |                                                                 |
+# |  Author      :                    Jean-Paul CHAPUT              |
+# |  E-mail      :            Jean-Paul.Chaput@lip6.fr              |
+# | =============================================================== |
+# |  Python      :       "./plugins/block/matrix.py"                |
+# +-----------------------------------------------------------------+
+
+
+import re
+import sys
+import os.path
+import Cfg
+from   operator  import itemgetter
+from   Hurricane import Breakpoint, DbU, Box, Transformation, Box, \
+                        Path, Layer, Occurrence, Net, RoutingPad,  \
+                        Horizontal, Vertical, Contact, Pin, Plug,  \
+                        Instance
+import CRL
+from   CRL             import RoutingLayerGauge
+from   helpers         import trace, l, u, n
+from   helpers         import dots
+from   helpers.io      import ErrorMessage, WarningMessage, catch
+from   helpers.overlay import UpdateSession
+from   plugins         import getParameter
+from   plugins.alpha   import utils
+
+
+af = CRL.AllianceFramework.get()
+
+
+class RegisterMatrix ( object ):
+
+    registerCell = af.getCell( 'sff1_x4', CRL.Catalog.State.Views )
+    
+    def __init__ ( self, conf, cell, pattern ):
+        if not RegisterMatrix.registerCell:
+            raise ErrorMessage( 1, 'Matrix.__init__(): DFF Cell "sff1_x4" has not been found in the libraries.' )
+        self.conf        = conf
+        self.pattern     = re.compile( pattern )
+        self.matrix      = [ [], ]
+        self.abutmentBox = Box()
+        for instance in cell.getInstances():
+            if instance.getMasterCell() != RegisterMatrix.registerCell:
+                continue
+            output = instance.getPlug( instance.getMasterCell().getNet( 'q' ) )
+            m = self.pattern.match( output.getNet().getName() )
+            if not m:
+                continue
+            i = int( m.group('i') )
+            j = int( m.group('j') )
+            if len(self.matrix) <= i:
+                while len(self.matrix) <= i:
+                    self.matrix.append( [] )
+            if len(self.matrix[i]) <= j:
+                while len(self.matrix[i]) <= j:
+                    self.matrix[i].append( None )
+            if self.matrix[i][j] is not None:
+                print( ErrorMessage( 1, 'Matrix.__init__(): Duplicated matrix element [{},{}]' \
+                                        .format(i,j) ) )
+                continue
+            self.matrix[i][j] = instance
+        columns = len( self.matrix[0] )
+        for i in range(1,self.rows):
+            if len(self.matrix[i]) != self.columns:
+                print( ErrorMessage( 1, 'Matrix.__init__(): Uneven matrix, column {} has a different size ({})' \
+                                        .format(i,len(self.matrix[i])) ) )
+            for j in range(len(self.matrix[i])):
+                if self.matrix[i][j] is None:
+                    print( ErrorMessage( 1, '[ERROR] Holed matrix @[{},{}]' \
+                                            .format(i,j) ) )
+        regAb = RegisterMatrix.registerCell.getAbutmentBox()
+        print( '   o  Matched matrix block on pattern "{}"'.format(self.pattern.pattern) )
+        print( '      - Size {} x {}, {} x {} ' \
+               .format( self.rows
+                      , self.columns
+                      , DbU.getValueString(regAb.getWidth ()*self.rows)
+                      , DbU.getValueString(regAb.getHeight()*self.columns)
+                      ))
+
+    @property
+    def rows ( self ):
+        return len(self.matrix)
+
+    @property
+    def columns ( self ):
+        return len(self.matrix[0])
+        
+    def toXPitch ( self, x ):
+        """
+        Returns the coordinate of the pitch immediately inferior to X.
+        If we are in a chip, compute coordinate in the *corona* system.
+        """
+        offset = 0
+        area   = self.conf.coreAb
+        if self.conf.isCoreBlock:
+            offset = self.conf.icore.getTransformation().getTx()
+            self.conf.icore.getTransformation().applyOn( area )
+        modulo = (x - offset - area.getXMin()) % self.conf.sliceStep 
+        return x - modulo
+
+    def toYSlice ( self, y ):
+        """
+        Returns the coordinate of the slice immediately inferior to Y.
+        If we are in a chip, compute coordinate in the *corona* system.
+        """
+        offset = 0
+        area   = self.conf.coreAb
+        if self.conf.isCoreBlock:
+            offset = self.conf.icore.getTransformation().getTy()
+            self.conf.icore.getTransformation().applyOn( area )
+        #trace( 540, '\toffset:{}\n'.format(DbU.getValueString(offset)) )
+        modulo = (y - offset - area.getYMin()) % self.conf.sliceHeight 
+        return y - modulo
+
+    def _getTransformation ( self, originX, originY ):
+        """Transform (originX,originY) into sliced coordinates relatives to the corona."""
+        yoffset = 0
+        if self.conf.isCoreBlock:
+            yoffset = self.conf.icore.getTransformation().getTy()
+        sliceHeight = self.conf.sliceHeight 
+        x           = self.toXPitch( originX )
+        y           = self.toYSlice( originY )
+        slice       = (y - yoffset) / sliceHeight
+        orientation = Transformation.Orientation.ID
+        y = slice * sliceHeight + yoffset
+        if slice % 2:
+            orientation = Transformation.Orientation.MY
+            y          += sliceHeight
+        transf = Transformation( x, y, orientation )
+        return transf
+
+    def getWidth ( self ):
+        width = RegisterMatrix.registerCell.getAbutmentBox().getWidth()
+        return width * self.rows
+
+    def getHeight ( self ):
+        height = RegisterMatrix.registerCell.getAbutmentBox().getHeight()
+        return height * self.columns
+
+    def getAbutmentBox ( self ):
+        return self.abutmentBox
+
+    def place ( self, origin ):
+        regAb       = RegisterMatrix.registerCell.getAbutmentBox()
+        sliceHeight = self.conf.sliceHeight 
+        regWidth    = regAb.getWidth()
+        x = origin.getX()
+        for i in range(self.rows):
+            y = origin.getY()
+            for j in range(self.columns):
+                instance = self.matrix[i][j]
+                instance.setTransformation ( self._getTransformation(x,y) )
+                instance.setPlacementStatus( Instance.PlacementStatus.FIXED )
+                #print( '{} placed @{}'.format(instance,instance.getTransformation()) )
+                y += sliceHeight
+            x += regWidth
+        self.abutmentBox = Box( origin.getX()
+                              , origin.getY()
+                              , origin.getX() + self.getWidth()
+                              , origin.getY() + self.getHeight() )