Add custom cell properties to technologies

this is technology specific database to store data about the custom
design cells. For now it only contains on which axis the bitcells are
mirrored. This is a first step to support thin cells that need to be
mirrored on the x and y axis.

Signed-off-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>

compiler/modules/base_array.py

@@ -7,6 +7,7 @@
 #
 import debug
 import design
+from tech import cell_properties
 
 class bitcell_base_array(design.design):
     """
@@ -93,8 +94,7 @@ class bitcell_base_array(design.design):
             yoffset = 0.0
             for row in range(self.row_size):
                 name = name_template.format(row, col)
-
-                if (row + row_offset) % 2:
+                if cell_properties.bitcell.mirror.x and (row + row_offset) % 2:
                     tempy = yoffset + self.cell.height
                     dir_key = "MX"
                 else:

compiler/modules/custom_cell_properties.py

@@ -0,0 +1,28 @@
+# See LICENSE for licensing information.
+#
+# Copyright (c) 2016-2020 Regents of the University of California and The Board
+# of Regents for the Oklahoma Agricultural and Mechanical College
+# (acting for and on behalf of Oklahoma State University)
+# All rights reserved.
+#
+
+class _MirrorAxis:
+    def __init__(self, x, y):
+        self.x = x
+        self.y = y
+
+class _Bitcell:
+    def __init__(self, mirror):
+        self.mirror = mirror
+
+class CellProperties():
+    """
+    TODO
+    """
+    def __init__(self):
+        self.names = {}
+        self._bitcell = _Bitcell(_MirrorAxis(True, False))
+
+    @property
+    def bitcell(self):
+        return self._bitcell

compiler/modules/replica_column.py

@@ -92,7 +92,7 @@ class replica_column(design.design):
             self.connect_inst(self.get_bitcell_pins(0, row))
             
     def place_instances(self):
-
+        from tech import cell_properties
         # Flip the mirrors if we have an odd number of replica+dummy rows at the bottom
         # so that we will start with mirroring rather than not mirroring
         rbl_offset = (self.left_rbl+1)%2
@@ -100,7 +100,7 @@ class replica_column(design.design):
         for row in range(self.total_size):
             name = "bit_r{0}_{1}".format(row,"rbl")
             offset = vector(0,self.cell.height*(row+(row+rbl_offset)%2))
-            if (row+rbl_offset)%2:
+            if cell_properties.bitcell.mirror.x and (row+rbl_offset)%2:
                 dir_key = "MX"
             else:
                 dir_key = "R0"

technology/freepdk45/tech/tech.py

@@ -8,6 +8,7 @@
 import os
 from design_rules import *
 from module_type import *
+from custom_cell_properties import CellProperties
 
 """
 File containing the process technology parameters for FreePDK 45nm.
@@ -24,6 +25,12 @@ File containing the process technology parameters for FreePDK 45nm.
 # For example: tech_modules['contact'] = 'contact_freepdk45'
 tech_modules = ModuleType()
 
+###################################################
+# Custom cell properties
+###################################################
+cell_properties = CellProperties()
+cell_properties.bitcell.mirror.x = True
+cell_properties.bitcell.mirror.y = False
 
 ###################################################
 # GDS file info

technology/scn3me_subm/tech/tech.py

@@ -1,6 +1,7 @@
 import os
 from design_rules import *
 from module_type import *
+from custom_cell_properties import CellProperties
 
 """
 File containing the process technology parameters for SCMOS 3me, subm, 180nm.
@@ -12,6 +13,13 @@ File containing the process technology parameters for SCMOS 3me, subm, 180nm.
 # For example: tech_modules['contact'] = 'contact_scn3me'
 tech_modules = ModuleType()
 
+###################################################
+# Custom cell properties
+###################################################
+cell_properties = CellProperties()
+cell_properties.bitcell.mirror.x = True
+cell_properties.bitcell.mirror.y = False
+
 #GDS file info
 GDS={}
 # gds units

technology/scn4m_subm/tech/tech.py

@@ -8,6 +8,7 @@
 import os
 from design_rules import *
 from module_type import *
+from custom_cell_properties import CellProperties
 
 """
 File containing the process technology parameters for SCMOS 4m, 0.35um
@@ -24,6 +25,12 @@ File containing the process technology parameters for SCMOS 4m, 0.35um
 # For example: tech_modules['contact'] = 'contact_scn4m'
 tech_modules = ModuleType()
 
+###################################################
+# Custom cell properties
+###################################################
+cell_properties = CellProperties()
+cell_properties.bitcell.mirror.x = True
+cell_properties.bitcell.mirror.y = False
 
 ###################################################
 # GDS file info