# See LICENSE for licensing information. # # Copyright (c) 2016-2023 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. # from openram import debug from openram.tech import cell_properties as props from .bitcell_base import bitcell_base class bitcell_2port(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. """ def __init__(self, name): super().__init__(name, prop=props.bitcell_2port) debug.info(2, "Create bitcell with 2 ports") self.bl_names = ["bl0", "bl1"] self.br_names = ["br0", "br1"] self.wl_names = ["wl0", "wl1"] 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 """ bitcell_pins = ["bl0_{0}".format(col), "br0_{0}".format(col), "bl1_{0}".format(col), "br1_{0}".format(col), "wl0_{0}".format(row), "wl1_{0}".format(row), "vdd", "gnd"] return bitcell_pins def get_all_wl_names(self): """ Creates a list of all wordline pin names """ return self.wl_names def get_all_bitline_names(self): """ Creates a list of all bitline pin names (both bl and br) """ return ["bl0", "br0", "bl1", "br1"] def get_all_bl_names(self): """ Creates a list of all bl pins names """ return ["bl0", "bl1"] def get_all_br_names(self): """ Creates a list of all br pins names """ return ["br0", "br1"] def get_read_bl_names(self): """ Creates a list of bl pin names associated with read ports """ return ["bl0", "bl1"] def get_read_br_names(self): """ Creates a list of br pin names associated with read ports """ return ["br0", "br1"] def get_write_bl_names(self): """ Creates a list of bl pin names associated with write ports """ return ["bl0"] def get_write_br_names(self): """ Creates a list of br pin names asscociated with write ports""" return ["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.get_original_pin_names(), port_nets)} # Edges hardcoded here. Essentially wl->bl/br for both ports. # Port 0 edges graph.add_edge(pin_dict["wl0"], pin_dict["bl0"], self) graph.add_edge(pin_dict["wl0"], pin_dict["br0"], self) # Port 1 edges graph.add_edge(pin_dict["wl1"], pin_dict["bl1"], self) graph.add_edge(pin_dict["wl1"], pin_dict["br1"], self)