Allow the Y position of the H-Tree horizontal branch to be set.

* Change: In cumulus.block.configuration and cumulus.block.htree, two new
    configuration parameters allow to specify the offset of the horizontal
    branch of the H-Tree manually:
        cfg.spares.htreeRootOffset (first level of the tree)
        cfg.spares.htreeOffset     (subsequent levels)
      The offset is given in number of tracks.

cumulus/src/plugins/block/configuration.py

@@ -25,7 +25,7 @@ from   ...CRL             import AllianceFramework, RoutingLayerGauge, Catalog,
                                  Gds, Spice
 from   ...helpers         import trace, l, u, n
 from   ...helpers.io      import ErrorMessage, WarningMessage, catch
-from   ...helpers.overlay import CfgCache, UpdateSession
+from   ...helpers.overlay import CfgCache, CfgDefault, UpdateSession
 from   ..                 import getParameter
 from   ..rsave            import rsave
 from   ..utils            import getPlugByName
@@ -80,7 +80,7 @@ class GaugeConf ( object ):
         self._plugToRp       = { }
         self._rpToAccess     = { }
         self._loadRoutingGauge()
-        self._routingBb      = Box()
+        self._routingBb       = Box()
         return
 
     @property
@@ -1403,6 +1403,8 @@ class BlockConf ( GaugeConf ):
         self.cfg.block.spareSide         = None
         self.cfg.block.vRailsPeriod      = None
         self.cfg.katana.dumpMeasures     = None
+        self.cfg.spares.htreeRootOffset  = CfgDefault(3)
+        self.cfg.spares.htreeOffset      = CfgDefault(5)
         self.chipConf = ChipConf( self )
         self.etesian  = None
         self.katana   = None

cumulus/src/plugins/block/htree.py

@@ -45,7 +45,7 @@ def unbitify ( rawName ):
 
 class HTree ( object ):
     """
-    Build a H-Tree on a net occurrene.
+    Build a H-Tree on a net occurrence.
     """
 
     def __init__ ( self, spares, treeNetOcc, index, flags ):
@@ -159,12 +159,12 @@ class HTree ( object ):
                or (qt.br and len(qt.br.buffers) > 1) \
                or (qt.tr and len(qt.tr.buffers) > 1):
                leafFlags |= GaugeConf.HAccess
-        yoffset = 3
+        yoffset = gaugeConf.cfg.spares.htreeRootOffset
         if not qt.isRoot():
             ckParentNet   = qt.bInputPlug(0).getNet()
             driverContact = gaugeConf.rpAccessByPlugName( qt.buffers[0], bufferConf.input, ckParentNet )
             driverY       = driverContact.getY()
-            yoffset       = 5
+            yoffset       = gaugeConf.cfg.spares.htreeOffset
             trace( 550, '\tdriverContact={}\n'.format( driverContact ))
         if qt.bl:
             trace( 550, '+,', '\tblContact\n' )