# 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 debug from tech import cell_properties as props import bitcell_base class bitcell_2port(bitcell_base.bitcell_base): """ A single bit cell (6T, 8T, etc.) This module implements the single memory cell used in the design. It is a hand-made cell, so the layout and netlist should be available in the technology library. """ pin_names = [props.bitcell.cell_2port.pin.bl0, props.bitcell.cell_2port.pin.br0, props.bitcell.cell_2port.pin.bl1, props.bitcell.cell_2port.pin.br1, props.bitcell.cell_2port.pin.wl0, props.bitcell.cell_2port.pin.wl1, props.bitcell.cell_2port.pin.vdd, props.bitcell.cell_2port.pin.gnd] type_list = ["OUTPUT", "OUTPUT", "OUTPUT", "OUTPUT", "INPUT", "INPUT", "POWER", "GROUND"] storage_nets = ['Q', 'Q_bar'] def __init__(self, name): super().__init__(name) debug.info(2, "Create bitcell with 2 ports") self.nets_match = self.do_nets_exist(self.storage_nets) pin_names = self.pin_names self.bl_names = [pin_names[0], pin_names[2]] self.br_names = [pin_names[1], pin_names[3]] self.wl_names = [pin_names[4], pin_names[5]] def get_bitcell_pins(self, col, row): """ Creates a list of connections in the bitcell, indexed by column and row, for instance use in bitcell_array """ pin_name = props.bitcell.cell_2port.pin bitcell_pins = ["{0}_{1}".format(pin_name.bl0, col), "{0}_{1}".format(pin_name.br0, col), "{0}_{1}".format(pin_name.bl1, col), "{0}_{1}".format(pin_name.br1, col), "{0}_{1}".format(pin_name.wl0, row), "{0}_{1}".format(pin_name.wl1, row), "vdd", "gnd"] return bitcell_pins def get_all_wl_names(self): """ Creates a list of all wordline pin names """ return [props.bitcell.cell_2port.pin.wl0, props.bitcell.cell_2port.pin.wl1] def get_all_bitline_names(self): """ Creates a list of all bitline pin names (both bl and br) """ return [props.bitcell.cell_2port.pin.bl0, props.bitcell.cell_2port.pin.br0, props.bitcell.cell_2port.pin.bl1, props.bitcell.cell_2port.pin.br1] def get_all_bl_names(self): """ Creates a list of all bl pins names """ return [props.bitcell.cell_2port.pin.bl0, props.bitcell.cell_2port.pin.bl1] def get_all_br_names(self): """ Creates a list of all br pins names """ return [props.bitcell.cell_2port.pin.br0, props.bitcell.cell_2port.pin.br1] def get_read_bl_names(self): """ Creates a list of bl pin names associated with read ports """ return [props.bitcell.cell_2port.pin.bl0, props.bitcell.cell_2port.pin.bl1] def get_read_br_names(self): """ Creates a list of br pin names associated with read ports """ return [props.bitcell.cell_2port.pin.br0, props.bitcell.cell_2port.pin.br1] def get_write_bl_names(self): """ Creates a list of bl pin names associated with write ports """ return [props.bitcell.cell_2port.pin.bl0] def get_write_br_names(self): """ Creates a list of br pin names asscociated with write ports""" return [props.bitcell.cell_2port.pin.br1] def get_bl_name(self, port=0): """Get bl name by port""" debug.check(port < 2, "Two ports for bitcell_2port only.") return self.bl_names[port] def get_br_name(self, port=0): """Get bl name by port""" debug.check(port < 2, "Two ports for bitcell_2port only.") return self.br_names[port] def get_wl_name(self, port=0): """Get wl name by port""" debug.check(port < 2, "Two ports for bitcell_2port only.") return self.wl_names[port] def build_graph(self, graph, inst_name, port_nets): """Adds edges to graph. Multiport bitcell timing graph is too complex to use the add_graph_edges function.""" pin_dict = {pin: port for pin, port in zip(self.pins, port_nets)} # Edges hardcoded here. Essentially wl->bl/br for both ports. # Port 0 edges pins = props.bitcell.cell_2port.pin graph.add_edge(pin_dict[pins.wl0], pin_dict[pins.bl0], self) graph.add_edge(pin_dict[pins.wl0], pin_dict[pins.br0], self) # Port 1 edges graph.add_edge(pin_dict[pins.wl1], pin_dict[pins.bl1], self) graph.add_edge(pin_dict[pins.wl1], pin_dict[pins.br1], self)