# See LICENSE for licensing information. # # Copyright (c) 2016-2019 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. # import hierarchy_design import debug from tech import drc import tech from vector import vector from sram_factory import factory import sys class contact(hierarchy_design.hierarchy_design): """ Object for a contact shape with its conductor enclosures. Creates a contact array minimum active or poly enclosure and metal1 enclosure. This class has enclosure on two or four sides of the contact. The direction specifies whether the first and second layer have asymmetric extension in the H or V direction. The well/implant_type is an option to add a select/implant layer enclosing the contact. This is necessary to import layouts into Magic which requires the select to be in the same GDS hierarchy as the contact. """ def __init__(self, layer_stack, dimensions=(1, 1), directions=None, implant_type=None, well_type=None, name=""): # This will ignore the name parameter since # we can guarantee a unique name here hierarchy_design.hierarchy_design.__init__(self, name) debug.info(4, "create contact object {0}".format(name)) self.add_comment("layers: {0}".format(layer_stack)) self.add_comment("dimensions: {0}".format(dimensions)) if implant_type or well_type: self.add_comment("implant type: {}\n".format(implant_type)) self.add_comment("well_type: {}\n".format(well_type)) self.is_well_contact = implant_type == well_type self.layer_stack = layer_stack self.dimensions = dimensions # Non-preferred directions if directions == "nonpref": first_dir = "H" if self.get_preferred_direction(layer_stack[0])=="V" else "V" second_dir = "H" if self.get_preferred_direction(layer_stack[2])=="V" else "V" self.directions = (first_dir, second_dir) # Preferred directions elif directions == "pref": self.directions = (tech.preferred_directions[layer_stack[0]], tech.preferred_directions[layer_stack[2]]) # User directions elif directions: self.directions = directions # Preferred directions else: self.directions = (tech.preferred_directions[layer_stack[0]], tech.preferred_directions[layer_stack[2]]) self.offset = vector(0, 0) self.implant_type = implant_type self.well_type = well_type # Module does not have pins, but has empty pin list. self.pins = [] self.create_layout() def create_layout(self): self.setup_layers() self.setup_layout_constants() self.create_contact_array() self.create_first_layer_enclosure() self.create_second_layer_enclosure() self.create_nitride_cut_enclosure() self.height = max(self.first_layer_position.y + self.first_layer_height, self.second_layer_position.y + self.second_layer_height) self.width = max(self.first_layer_position.x + self.first_layer_width, self.second_layer_position.x + self.second_layer_width) # Do not include the select layer in the height/width if self.implant_type and self.well_type: self.create_implant_well_enclosures() elif self.implant_type or self.well_type: debug.error(-1, "Must define both implant and well type or none.") def setup_layers(self): """ Locally assign the layer names. """ (first_layer, via_layer, second_layer) = self.layer_stack self.first_layer_name = first_layer self.second_layer_name = second_layer # Contacts will have unique per first layer if via_layer in tech.layer: self.via_layer_name = via_layer elif via_layer == "contact": if first_layer in ("active", "poly"): self.via_layer_name = first_layer + "_" + via_layer elif second_layer in ("active", "poly"): self.via_layer_name = second_layer + "_" + via_layer else: debug.error("Invalid via layer {}".format(via_layer), -1) else: debug.error("Invalid via layer {}".format(via_layer), -1) def setup_layout_constants(self): """ Determine the design rules for the enclosure layers """ self.contact_width = drc("minwidth_{0}". format(self.via_layer_name)) contact_to_contact = drc("{0}_to_{0}".format(self.via_layer_name)) self.contact_pitch = self.contact_width + contact_to_contact self.contact_array_width = self.contact_width + (self.dimensions[0] - 1) * self.contact_pitch self.contact_array_height = self.contact_width + (self.dimensions[1] - 1) * self.contact_pitch # DRC rules # The extend rule applies to asymmetric enclosures in one direction. # The enclosure rule applies to symmetric enclosure component. self.first_layer_minwidth = drc("minwidth_{0}".format(self.first_layer_name)) self.first_layer_enclosure = drc("{0}_enclose_{1}".format(self.first_layer_name, self.via_layer_name)) # If there's a different rule for active # FIXME: Make this more elegant if self.is_well_contact and self.first_layer_name == "active" and "tap_extend_contact" in drc.keys(): self.first_layer_extend = drc("tap_extend_contact") else: self.first_layer_extend = drc("{0}_extend_{1}".format(self.first_layer_name, self.via_layer_name)) self.second_layer_minwidth = drc("minwidth_{0}".format(self.second_layer_name)) self.second_layer_enclosure = drc("{0}_enclose_{1}".format(self.second_layer_name, self.via_layer_name)) self.second_layer_extend = drc("{0}_extend_{1}".format(self.second_layer_name, self.via_layer_name)) # In some technologies, the minimum width may be larger # than the overlap requirement around the via, so # check this for each dimension. if self.directions[0] == "V": self.first_layer_horizontal_enclosure = max(self.first_layer_enclosure, (self.first_layer_minwidth - self.contact_array_width) / 2) self.first_layer_vertical_enclosure = max(self.first_layer_extend, (self.first_layer_minwidth - self.contact_array_height) / 2) elif self.directions[0] == "H": self.first_layer_horizontal_enclosure = max(self.first_layer_extend, (self.first_layer_minwidth - self.contact_array_width) / 2) self.first_layer_vertical_enclosure = max(self.first_layer_enclosure, (self.first_layer_minwidth - self.contact_array_height) / 2) else: debug.error("Invalid first layer direction: ".format(self.directions[0]), -1) # In some technologies, the minimum width may be larger # than the overlap requirement around the via, so # check this for each dimension. if self.directions[1] == "V": self.second_layer_horizontal_enclosure = max(self.second_layer_enclosure, (self.second_layer_minwidth - self.contact_array_width) / 2) self.second_layer_vertical_enclosure = max(self.second_layer_extend, (self.second_layer_minwidth - self.contact_array_height) / 2) elif self.directions[1] == "H": self.second_layer_horizontal_enclosure = max(self.second_layer_extend, (self.second_layer_minwidth - self.contact_array_height) / 2) self.second_layer_vertical_enclosure = max(self.second_layer_enclosure, (self.second_layer_minwidth - self.contact_array_width) / 2) else: debug.error("Invalid secon layer direction: ".format(self.directions[1]), -1) def create_contact_array(self): """ Create the contact array at the origin""" # offset for the via array self.via_layer_position = vector( max(self.first_layer_horizontal_enclosure, self.second_layer_horizontal_enclosure), max(self.first_layer_vertical_enclosure, self.second_layer_vertical_enclosure)) for i in range(self.dimensions[1]): offset = self.via_layer_position + vector(0, self.contact_pitch * i) for j in range(self.dimensions[0]): self.add_rect(layer=self.via_layer_name, offset=offset, width=self.contact_width, height=self.contact_width) offset = offset + vector(self.contact_pitch, 0) def create_nitride_cut_enclosure(self): """ Special layer that encloses poly contacts in some processes """ # Check if there is a special poly nitride cut layer if "npc" not in tech.layer: return # Only add for poly layers if self.first_layer_name == "poly": self.add_rect(layer="npc", offset=self.first_layer_position, width=self.first_layer_width, height=self.first_layer_height) elif self.second_layer_name == "poly": self.add_rect(layer="npc", offset=self.second_layer_position, width=self.second_layer_width, height=self.second_layer_height) def create_first_layer_enclosure(self): # this is if the first and second layers are different self.first_layer_position = vector( max(self.second_layer_horizontal_enclosure - self.first_layer_horizontal_enclosure, 0), max(self.second_layer_vertical_enclosure - self.first_layer_vertical_enclosure, 0)) self.first_layer_width = max(self.contact_array_width + 2 * self.first_layer_horizontal_enclosure, self.first_layer_minwidth) self.first_layer_height = max(self.contact_array_height + 2 * self.first_layer_vertical_enclosure, self.first_layer_minwidth) self.add_rect(layer=self.first_layer_name, offset=self.first_layer_position, width=self.first_layer_width, height=self.first_layer_height) def create_second_layer_enclosure(self): # this is if the first and second layers are different self.second_layer_position = vector( max(self.first_layer_horizontal_enclosure - self.second_layer_horizontal_enclosure, 0), max(self.first_layer_vertical_enclosure - self.second_layer_vertical_enclosure, 0)) self.second_layer_width = max(self.contact_array_width + 2 * self.second_layer_horizontal_enclosure, self.second_layer_minwidth) self.second_layer_height = max(self.contact_array_height + 2 * self.second_layer_vertical_enclosure, self.second_layer_minwidth) self.add_rect(layer=self.second_layer_name, offset=self.second_layer_position, width=self.second_layer_width, height=self.second_layer_height) def create_implant_well_enclosures(self): implant_position = self.first_layer_position - [drc("implant_enclose_active")] * 2 implant_width = self.first_layer_width + 2 * drc("implant_enclose_active") implant_height = self.first_layer_height + 2 * drc("implant_enclose_active") self.add_rect(layer="{}implant".format(self.implant_type), offset=implant_position, width=implant_width, height=implant_height) # Optionally implant well if layer exists well_layer = "{}well".format(self.well_type) if well_layer in tech.layer: well_width_rule = drc("minwidth_" + well_layer) self.well_enclose_active = drc(well_layer + "_enclose_active") self.well_width = max(self.first_layer_width + 2 * self.well_enclose_active, well_width_rule) self.well_height = max(self.first_layer_height + 2 * self.well_enclose_active, well_width_rule) center_pos = vector(0.5*self.width, 0.5*self.height) well_position = center_pos - vector(0.5*self.well_width, 0.5*self.well_height) self.add_rect(layer=well_layer, offset=well_position, width=self.well_width, height=self.well_height) def analytical_power(self, corner, load): """ Get total power of a module """ return self.return_power() # Set up a static for each layer to be used for measurements for layer_stack in tech.layer_stacks: (layer1, via, layer2) = layer_stack cont = factory.create(module_type="contact", layer_stack=layer_stack) module = sys.modules[__name__] # Also create a contact that is just the first layer if layer1 == "poly" or layer1 == "active": setattr(module, layer1 + "_contact", cont) else: setattr(module, layer1 + "_via", cont) # Set up a static for each well contact for measurements if "nwell" in tech.layer: cont = factory.create(module_type="contact", layer_stack=tech.active_stack, implant_type="n", well_type="n") module = sys.modules[__name__] setattr(module, "nwell_contact", cont) if "pwell" in tech.layer: cont = factory.create(module_type="contact", layer_stack=tech.active_stack, implant_type="p", well_type="p") module = sys.modules[__name__] setattr(module, "pwell_contact", cont)