OpenRAM/compiler/bitcells/bitcell_1rw_1r.py

124 lines
4.6 KiB
Python

# 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
import utils
from tech import GDS, layer, parameter, drc
import logical_effort
import bitcell_base
class bitcell_1rw_1r(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 = ["bl0", "br0", "bl1", "br1", "wl0", "wl1", "vdd", "gnd"]
type_list = ["OUTPUT", "OUTPUT", "OUTPUT", "OUTPUT",
"INPUT", "INPUT", "POWER", "GROUND"]
storage_nets = ['Q', 'Q_bar']
(width, height) = utils.get_libcell_size("cell_1rw_1r",
GDS["unit"],
layer["boundary"])
pin_map = utils.get_libcell_pins(pin_names, "cell_1rw_1r", GDS["unit"])
def __init__(self, name=""):
# Ignore the name argument
bitcell_base.bitcell_base.__init__(self, "cell_1rw_1r")
debug.info(2, "Create bitcell with 1RW and 1R Port")
self.width = bitcell_1rw_1r.width
self.height = bitcell_1rw_1r.height
self.pin_map = bitcell_1rw_1r.pin_map
self.add_pin_types(self.type_list)
self.nets_match = self.do_nets_exist(self.storage_nets)
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 """
row_pins = ["wl0", "wl1"]
return row_pins
def get_all_bitline_names(self):
""" Creates a list of all bitline pin names (both bl and br) """
column_pins = ["bl0", "br0", "bl1", "br1"]
return column_pins
def get_all_bl_names(self):
""" Creates a list of all bl pins names """
column_pins = ["bl0", "bl1"]
return column_pins
def get_all_br_names(self):
""" Creates a list of all br pins names """
column_pins = ["br0", "br1"]
return column_pins
def get_read_bl_names(self):
""" Creates a list of bl pin names associated with read ports """
column_pins = ["bl0", "bl1"]
return column_pins
def get_read_br_names(self):
""" Creates a list of br pin names associated with read ports """
column_pins = ["br0", "br1"]
return column_pins
def get_write_bl_names(self):
""" Creates a list of bl pin names associated with write ports """
column_pins = ["bl0"]
return column_pins
def get_write_br_names(self):
""" Creates a list of br pin names asscociated with write ports"""
column_pins = ["br0"]
return column_pins
def get_bl_name(self, port=0):
"""Get bl name by port"""
debug.check(port < 2, "Two ports for bitcell_1rw_1r only.")
return "bl{}".format(port)
def get_br_name(self, port=0):
"""Get bl name by port"""
debug.check(port < 2, "Two ports for bitcell_1rw_1r only.")
return "br{}".format(port)
def get_wl_name(self, port=0):
"""Get wl name by port"""
debug.check(port < 2, "Two ports for bitcell_1rw_1r only.")
return "wl{}".format(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
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)