Vdd/gnd via stacks now use perferred directions, added cell property to override

compiler/base/hierarchy_layout.py

@@ -1201,10 +1201,16 @@ class layout():
         the given center location. The starting layer is specified to determine
         which vias are needed.
         """
+
+        # Force vdd/gnd via stack to be vertically or horizontally oriented
+        # Default: None, uses prefered metal directions
         if vertical:
             direction = ("V", "V")
-        else:
+        elif not vertical and vertical is not None:
             direction = ("H", "H")
+        else:
+            direction = None
+
 
         via = self.add_via_stack_center(from_layer=start_layer,
                                         to_layer=self.pwr_grid_layer,
@@ -1390,4 +1396,3 @@ class layout():
             debug.info(0, "name={0} : mod={1} : offset={2}".format(inst.name,
                                                                    inst.mod.name,
                                                                    inst.offset))
-

compiler/modules/bitcell_base_array.py

@@ -101,13 +101,20 @@ class bitcell_base_array(design.design):
                                     width=self.width,
                                     height=wl_pin.height())
 
-        # For every second row and column, add a via for gnd and vdd
+        # For non-square via stacks, vertical/horizontal direction refers to the stack orientation in 2d space
+        # Default uses prefered directions for each layer; this cell property is only currently used by s8 tech (03/20)
+        try:
+            force_power_pins_vertical = cell_properties.bitcell_force_power_pins_vertical
+        except AttributeError:
+            force_power_pins_vertical = None
+
+        # Add vdd/gnd via stacks
         for row in range(self.row_size):
             for col in range(self.column_size):
                 inst = self.cell_inst[row,col]
                 for pin_name in ["vdd", "gnd"]:
                     for pin in inst.get_pins(pin_name):
-                        self.add_power_pin(name=pin_name, loc=pin.center(), vertical=True, start_layer=pin.layer)
+                        self.add_power_pin(name=pin_name, loc=pin.center(), vertical=force_power_pins_vertical, start_layer=pin.layer)
 
     def _adjust_x_offset(self, xoffset, col, col_offset):
         tempx = xoffset