Add option to remove wells. Save area in pgates with redundant wells.

compiler/pgates/pand2.py

@@ -15,14 +15,14 @@ class pand2(pgate.pgate):
     """
     This is a simple buffer used for driving loads.
     """
-    def __init__(self, name, size=1, height=None, vertical=False):
+    def __init__(self, name, size=1, height=None, vertical=False, add_wells=True):
         debug.info(1, "Creating pand2 {}".format(name))
         self.add_comment("size: {}".format(size))
 
         self.vertical = vertical
         self.size = size
 
-        pgate.pgate.__init__(self, name)
+        pgate.pgate.__init__(self, name, height, add_wells)
 
     def create_netlist(self):
         self.add_pins()
@@ -31,12 +31,15 @@ class pand2(pgate.pgate):
 
     def create_modules(self):
         self.nand = factory.create(module_type="pnand2",
-                                   height=self.height)
-        self.add_mod(self.nand)
+                                   height=self.height,
+                                   add_wells=False)
 
         self.inv = factory.create(module_type="pdriver",
                                   size_list=[self.size],
-                                  height=self.height)
+                                  height=self.height,
+                                  add_wells=self.add_wells)
+            
+        self.add_mod(self.nand)
         self.add_mod(self.inv)
 
     def create_layout(self):

compiler/pgates/pand3.py

@@ -15,7 +15,7 @@ class pand3(pgate.pgate):
     """
     This is a simple buffer used for driving loads.
     """
-    def __init__(self, name, size=1, height=None, vertical=False):
+    def __init__(self, name, size=1, height=None, vertical=False, add_wells=True):
         debug.info(1, "Creating pand3 {}".format(name))
         self.add_comment("size: {}".format(size))
 
@@ -23,7 +23,7 @@ class pand3(pgate.pgate):
         self.size = size
         
         # Creates the netlist and layout
-        pgate.pgate.__init__(self, name, height)
+        pgate.pgate.__init__(self, name, height, add_wells)
 
     def create_netlist(self):
         self.add_pins()
@@ -33,12 +33,17 @@ class pand3(pgate.pgate):
     def create_modules(self):
         # Shield the cap, but have at least a stage effort of 4
         self.nand = factory.create(module_type="pnand3",
-                                   height=self.height)
-        self.add_mod(self.nand)
+                                   height=self.height,
+                                   add_wells=False)
 
+        # Add the well tap to the inverter because when stacked
+        # vertically it is sometimes narrower
         self.inv = factory.create(module_type="pdriver",
                                   size_list=[self.size],
-                                  height=self.height)
+                                  height=self.height,
+                                  add_wells=self.add_wells)
+
+        self.add_mod(self.nand)
         self.add_mod(self.inv)
 
     def create_layout(self):

compiler/pgates/pdriver.py

@@ -17,7 +17,7 @@ class pdriver(pgate.pgate):
     sized for driving a load.
     """
     
-    def __init__(self, name, neg_polarity=False, fanout=0, size_list=None, height=None):
+    def __init__(self, name, neg_polarity=False, fanout=0, size_list=None, height=None, add_wells=True):
 
         debug.info(1, "creating pdriver {}".format(name))
 
@@ -35,7 +35,7 @@ class pdriver(pgate.pgate):
             debug.error("Cannot specify both size_list and neg_polarity.", -1)
  
         # Creates the netlist and layout
-        pgate.pgate.__init__(self, name, height)
+        pgate.pgate.__init__(self, name, height, add_wells)
         
     def compute_sizes(self):
         # size_list specified
@@ -73,9 +73,9 @@ class pdriver(pgate.pgate):
         self.place_modules()
         self.route_wires()
         self.add_layout_pins()
-
         self.width = self.inv_inst_list[-1].rx()
         self.height = self.inv_inst_list[0].height
+        self.extend_wells()
         self.route_supply_rails()
         self.add_boundary()
         
@@ -87,7 +87,7 @@ class pdriver(pgate.pgate):
 
     def add_modules(self):
         self.inv_list = []
-        add_well = True
+        add_well = self.add_wells
         for size in self.size_list:
             temp_inv = factory.create(module_type="pinv",
                                       size=size,

compiler/pgates/pgate.py

@@ -162,12 +162,12 @@ class pgate(design.design):
             nwell_height = nwell_max_offset - self.nwell_y_offset
             self.add_rect(layer="nwell",
                           offset=nwell_position,
-                          width=self.well_width,
+                          width=self.width + 2 * self.well_extend_active,
                           height=nwell_height)
             if "vtg" in layer:
                 self.add_rect(layer="vtg",
                               offset=nwell_position,
-                              width=self.well_width,
+                              width=self.width + 2 * self.well_extend_active,
                               height=nwell_height)
 
         # Start this half a rail width below the cell
@@ -178,12 +178,12 @@ class pgate(design.design):
             pwell_height = self.nwell_y_offset - pwell_position.y
             self.add_rect(layer="pwell",
                           offset=pwell_position,
-                          width=self.well_width,
+                          width=self.width + 2 * self.well_extend_active,
                           height=pwell_height)
             if "vtg" in layer:
                 self.add_rect(layer="vtg",
                               offset=pwell_position,
-                              width=self.well_width,
+                              width=self.width + 2 * self.well_extend_active,
                               height=pwell_height)
 
     def add_nwell_contact(self, pmos, pmos_pos):
@@ -304,16 +304,17 @@ class pgate(design.design):
     def determine_width(self):
         """ Determine the width based on the well contacts (assumed to be on the right side) """
 
+        # It was already set or is left as default (minimum)
         # Width is determined by well contact and spacing and allowing a supply via between each cell
         if self.add_wells:
-            self.width = max(self.nwell_contact.rx(), self.pwell_contact.rx()) + self.m1_space + 0.5 * contact.m1_via.width
+            width = max(self.nwell_contact.rx(), self.pwell_contact.rx()) + self.m1_space + 0.5 * contact.m1_via.width
             # Height is an input parameter, so it is not recomputed.
         else:
             max_active_xoffset = self.find_highest_layer_coords("active").x
             max_route_xoffset = self.find_highest_layer_coords(self.route_layer).x + 0.5 * self.m1_space
-            self.width = max(max_active_xoffset, max_route_xoffset)
-
-        self.well_width = self.width + 2 * self.nwell_enclose_active
+            width = max(max_active_xoffset, max_route_xoffset)
+            
+        self.width = width
 
     @staticmethod
     def bin_width(tx_type, target_width):

compiler/pgates/pinv.py

@@ -60,14 +60,14 @@ class pinv(pgate.pgate):
             self.add_well_contacts()
         self.determine_width()
         self.extend_wells()
-        self.route_supply_rails()
-        self.connect_rails()
         self.route_input_gate(self.pmos_inst,
                               self.nmos_inst,
                               self.output_pos.y,
                               "A",
                               position="farleft")
         self.route_outputs()
+        self.route_supply_rails()
+        self.connect_rails()
         self.add_boundary()
         
     def add_pins(self):

compiler/pgates/pnand2.py

@@ -5,7 +5,6 @@
 # (acting for and on behalf of Oklahoma State University)
 # All rights reserved.
 #
-import contact
 import pgate
 import debug
 from tech import drc, parameter, spice

compiler/pgates/single_level_column_mux.py

@@ -50,7 +50,7 @@ class single_level_column_mux(pgate.pgate):
         self.connect_poly()
         self.add_bitline_pins()
         self.connect_bitlines()
-        self.add_wells()
+        self.add_pn_wells()
 
     def add_modules(self):
         self.bitcell = factory.create(module_type="bitcell")
@@ -218,7 +218,7 @@ class single_level_column_mux(pgate.pgate):
         self.add_path(self.col_mux_stack[2],
                       [br_pin.bc(), mid1, mid2, nmos_lower_d_pin.center()])
 
-    def add_wells(self):
+    def add_pn_wells(self):
         """
         Add a well and implant over the whole cell. Also, add the
         pwell contact (if it exists)

compiler/tests/04_pnor2_test.py

@@ -25,10 +25,6 @@ class pnor2_test(openram_test):
         tx = factory.create(module_type="pnor2", size=1)
         self.local_check(tx)
 
-        debug.info(2, "Checking 2-input nor gate")
-        tx = factory.create(module_type="pnor2", size=1, add_wells=False)
-        self.local_drc_check(tx)
-        
         globals.end_openram()
         
 # run the test from the command line