OpenRAM/compiler/modules/global_bitcell_array.py

271 lines
11 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 bitcell_base_array
from globals import OPTS
from sram_factory import factory
from vector import vector
import debug
from numpy import cumsum
class global_bitcell_array(bitcell_base_array.bitcell_base_array):
"""
Creates a global bitcell array.
Rows is an integer number for all local arrays.
Cols is a list of the array widths.
"""
def __init__(self, rows, cols, name=""):
# The total of all columns will be the number of columns
super().__init__(name=name, rows=rows, cols=sum(cols), column_offset=0)
self.column_sizes = cols
self.col_offsets = [0] + list(cumsum(cols)[:-1])
debug.check(len(self.all_ports)<=2, "Only support dual port or less in global bitcell array.")
self.rbl = [1, 1 if len(self.all_ports)>1 else 0]
self.create_netlist()
if not OPTS.netlist_only:
self.create_layout()
def create_netlist(self):
""" Create and connect the netlist """
self.add_modules()
self.add_pins()
self.create_instances()
def create_layout(self):
self.place()
self.route()
self.add_layout_pins()
self.add_boundary()
self.DRC_LVS()
def add_modules(self):
""" Add the modules used in this design """
self.local_mods = []
# Special case of a single local array
# so it should contain the left and possibly right RBL
if len(self.column_sizes) == 1:
la = factory.create(module_type="local_bitcell_array",
rows=self.row_size,
cols=self.column_sizes[0],
rbl=self.rbl,
left_rbl=[0],
right_rbl=[1] if len(self.all_ports) > 1 else [])
self.add_mod(la)
self.local_mods.append(la)
return
for i, cols in enumerate(self.column_sizes):
# Always add the left RBLs to the first subarray
if i == 0:
la = factory.create(module_type="local_bitcell_array",
rows=self.row_size,
cols=cols,
rbl=self.rbl,
left_rbl=[0])
# Add the right RBL to the last subarray
elif i == len(self.column_sizes) - 1 and len(self.all_ports) > 1:
la = factory.create(module_type="local_bitcell_array",
rows=self.row_size,
cols=cols,
rbl=self.rbl,
right_rbl=[1])
# Middle subarrays do not have any RBLs
else:
la = factory.create(module_type="local_bitcell_array",
rows=self.row_size,
cols=cols,
rbl=self.rbl)
self.add_mod(la)
self.local_mods.append(la)
def add_pins(self):
self.add_bitline_pins()
self.add_wordline_pins()
self.add_pin("vdd", "POWER")
self.add_pin("gnd", "GROUND")
def add_bitline_pins(self):
self.bitline_names = [[] for x in self.all_ports]
self.rbl_bitline_names = [[] for x in self.all_ports]
for port in self.all_ports:
self.rbl_bitline_names[0].append("rbl_bl_{}_0".format(port))
for port in self.all_ports:
self.rbl_bitline_names[0].append("rbl_br_{}_0".format(port))
for col in range(self.column_size):
for port in self.all_ports:
self.bitline_names[port].append("bl_{0}_{1}".format(port, col))
for port in self.all_ports:
self.bitline_names[port].append("br_{0}_{1}".format(port, col))
if len(self.all_ports) > 1:
for port in self.all_ports:
self.rbl_bitline_names[1].append("rbl_bl_{}_1".format(port))
for port in self.all_ports:
self.rbl_bitline_names[1].append("rbl_br_{}_1".format(port))
# Make a flat list too
self.all_bitline_names = [x for sl in zip(*self.bitline_names) for x in sl]
# Make a flat list too
self.all_rbl_bitline_names = [x for sl in zip(*self.rbl_bitline_names) for x in sl]
self.add_pin_list(self.rbl_bitline_names[0], "INOUT")
self.add_pin_list(self.all_bitline_names, "INOUT")
if len(self.all_ports) > 1:
self.add_pin_list(self.rbl_bitline_names[1], "INOUT")
def add_wordline_pins(self):
self.rbl_wordline_names = [[] for x in self.all_ports]
self.wordline_names = [[] for x in self.all_ports]
for bit in self.all_ports:
for port in self.all_ports:
self.rbl_wordline_names[port].append("rbl_wl_{0}_{1}".format(port, bit))
self.all_rbl_wordline_names = [x for sl in zip(*self.rbl_wordline_names) for x in sl]
# Regular WLs
for row in range(self.row_size):
for port in self.all_ports:
self.wordline_names[port].append("wl_{0}_{1}".format(port, row))
self.all_wordline_names = [x for sl in zip(*self.wordline_names) for x in sl]
for port in range(self.rbl[0]):
self.add_pin(self.rbl_wordline_names[port][port], "INPUT")
self.add_pin_list(self.all_wordline_names, "INPUT")
for port in range(self.rbl[0], self.rbl[0] + self.rbl[1]):
self.add_pin(self.rbl_wordline_names[port][port], "INPUT")
def create_instances(self):
""" Create the module instances used in this design """
self.local_insts = []
for col, mod in zip(self.col_offsets, self.local_mods):
name = "la_{0}".format(col)
self.local_insts.append(self.add_inst(name=name,
mod=mod))
temp = []
if col == 0:
temp.extend(self.get_rbl_bitline_names(0))
port_inouts = [x for x in mod.get_inouts() if x.startswith("bl") or x.startswith("br")]
for pin_name in port_inouts:
# Offset of the last underscore that defines the bit number
bit_index = pin_name.rindex('_')
# col is the bit offset of the local array,
# while col_value is the offset within this array
col_value = int(pin_name[bit_index + 1:])
# Name of signal without the bit
base_name = pin_name[:bit_index]
# Strip the bit and add the new one
new_name = "{0}_{1}".format(base_name, col + col_value)
temp.append(new_name)
if len(self.all_ports) > 1 and mod == self.local_mods[-1]:
temp.extend(self.get_rbl_bitline_names(1))
for port in self.all_ports:
port_inputs = [x for x in mod.get_inputs() if "wl_{}".format(port) in x]
temp.extend(port_inputs)
temp.append("vdd")
temp.append("gnd")
self.connect_inst(temp)
def place(self):
offset = vector(0, 0)
for inst in self.local_insts:
inst.place(offset)
offset = inst.rx() + 3 * self.m3_pitch
self.height = self.local_mods[0].height
self.width = self.local_insts[-1].rx()
def route(self):
pass
def add_layout_pins(self):
# Regular bitlines
for col, inst in zip(self.col_offsets, self.local_insts):
for port in self.all_ports:
port_inouts = [x for x in inst.mod.get_inouts() if x.startswith("bl_{}".format(port)) or x.startswith("br_{}".format(port))]
for pin_name in port_inouts:
# Offset of the last underscore that defines the bit number
bit_index = pin_name.rindex('_')
# col is the bit offset of the local array,
# while col_value is the offset within this array
col_value = int(pin_name[bit_index + 1:])
# Name of signal without the bit
base_name = pin_name[:bit_index]
# Strip the bit and add the new one
new_name = "{0}_{1}".format(base_name, col + col_value)
self.copy_layout_pin(inst, pin_name, new_name)
for wl_name in self.local_mods[0].get_inputs():
left_pin = self.local_insts[0].get_pin(wl_name)
right_pin = self.local_insts[-1].get_pin(wl_name)
self.add_layout_pin_segment_center(text=wl_name,
layer=left_pin.layer,
start=left_pin.lc(),
end=right_pin.rc())
# Replica bitlines
self.copy_layout_pin(self.local_insts[0], "rbl_bl_0_0")
self.copy_layout_pin(self.local_insts[0], "rbl_br_0_0")
if len(self.all_ports) > 1:
self.copy_layout_pin(self.local_insts[0], "rbl_bl_1_0")
self.copy_layout_pin(self.local_insts[0], "rbl_br_1_0")
self.copy_layout_pin(self.local_insts[-1], "rbl_bl_0_1")
self.copy_layout_pin(self.local_insts[-1], "rbl_br_0_1")
self.copy_layout_pin(self.local_insts[-1], "rbl_bl_1_1")
self.copy_layout_pin(self.local_insts[-1], "rbl_br_1_1")
for inst in self.insts:
self.copy_power_pins(inst, "vdd")
self.copy_power_pins(inst, "gnd")
def get_main_array_top(self):
return self.local_insts[0].offset.y + self.local_mods[0].get_main_array_top()
def get_main_array_bottom(self):
return self.local_insts[0].offset.y + self.local_mods[0].get_main_array_bottom()
def get_main_array_left(self):
return self.local_insts[0].offset.x + self.local_mods[0].get_main_array_left()
def get_main_array_right(self):
return self.local_insts[-1].offset.x + self.local_mods[-1].get_main_array_right()
def get_column_offsets(self):
"""
Return an array of the x offsets of all the regular bits
"""
offsets = []
for inst in self.local_insts:
offsets.extend(inst.lx() + x for x in inst.mod.get_column_offsets())
return offsets