OpenRAM/compiler/wordline_driver.py

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Python
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2016-11-08 18:57:35 +01:00
from tech import drc, parameter, cell
import debug
import design
from math import log
from math import sqrt
import math
from pinv import pinv
from nand_2 import nand_2
from vector import vector
from globals import OPTS
class wordline_driver(design.design):
"""
Creates a Wordline Driver
Generates the wordline-driver to drive the bitcell
"""
def __init__(self, name, rows):
design.design.__init__(self, name)
self.rows = rows
self.add_pins()
self.design_layout()
self.DRC_LVS()
def add_pins(self):
# inputs to wordline_driver.
for i in range(self.rows):
self.add_pin("decode_out[{0}]".format(i))
# Outputs from wordline_driver.
for i in range(self.rows):
self.add_pin("wl[{0}]".format(i))
self.add_pin("clk")
self.add_pin("vdd")
self.add_pin("gnd")
def design_layout(self):
self.add_layout()
self.offsets_of_gates()
self.create_layout()
def add_layout(self):
self.inv = pinv(name="pinverter",
nmos_width=drc["minwidth_tx"],
beta=parameter["pinv_beta"])
self.add_mod(self.inv)
self.NAND2 = nand_2(name="pnand2",
nmos_width=2*drc["minwidth_tx"])
self.add_mod(self.NAND2)
def offsets_of_gates(self):
self.x_offset0 = 2 * drc["minwidth_metal1"] + 5 * drc["metal1_to_metal1"]
self.x_offset1 = self.x_offset0 + self.inv.width
self.x_offset2 = self.x_offset1 + self.NAND2.width
self.width = self.x_offset2 + self.inv.width
self.height = self.inv.height * self.rows
# Defining offset postions
self.decode_out_positions = []
self.clk_positions = []
self.WL_positions = []
self.vdd_positions = []
self.gnd_positions = []
def create_layout(self):
# Clk connection
self.add_rect(layer="metal1",
offset=[drc["minwidth_metal1"] + 2 * drc["metal1_to_metal1"],
2 * drc["minwidth_metal1"]],
width=drc["minwidth_metal1"],
height=self.height + 4*drc["minwidth_metal1"])
self.clk_positions.append([drc["minwidth_metal1"] + 2*drc["metal1_to_metal1"],
self.height])
self.add_label(text="clk",
layer="metal1",
offset=self.clk_positions[0])
for row in range(self.rows):
name_inv1 = "Wordline_driver_inv_clk%d" % (row)
name_nand = "Wordline_driver_nand%d" % (row)
name_inv2 = "Wordline_driver_inv%d" % (row)
# Extend vdd and gnd of Wordline_driver
yoffset = (row + 1) * self.inv.height - 0.5 * drc["minwidth_metal2"]
self.add_rect(layer="metal2",
offset=[0, yoffset],
width=self.x_offset0,
height=drc["minwidth_metal2"])
self.add_via(layers=("metal1", "via1", "metal2"),
offset=[drc["minwidth_metal1"], yoffset],
mirror="R90")
self.add_via(layers=("metal1", "via1", "metal2"),
offset=[self.x_offset0 + drc["minwidth_metal1"],
yoffset],
mirror="R90")
inv_nand2B_connection_height = (abs(self.inv.Z_position.y
- self.NAND2.B_position.y)
+ drc["minwidth_metal1"])
if (row % 2):
y_offset = self.inv.height*(row + 1)
name_inv1_offset = [self.x_offset0, y_offset]
nand2_offset=[self.x_offset1, y_offset]
inv2_offset=[self.x_offset2, y_offset]
inst_mirror = "MX"
cell_dir = vector(0,-1)
m1tm2_rotate=270
m1tm2_mirror="R0"
else:
y_offset = self.inv.height*row
name_inv1_offset = [self.x_offset0, y_offset]
nand2_offset=[self.x_offset1, y_offset]
inv2_offset=[self.x_offset2, y_offset]
inst_mirror = "R0"
cell_dir = vector(0,1)
m1tm2_rotate=90
m1tm2_mirror="MX"
# add inv1 based on the info above
self.add_inst(name=name_inv1,
mod=self.inv,
offset=name_inv1_offset,
mirror=inst_mirror )
self.connect_inst(["clk", "clk_bar[{0}]".format(row),
"vdd", "gnd"])
# add nand 2
self.add_inst(name=name_nand,
mod=self.NAND2,
offset=nand2_offset,
mirror=inst_mirror)
self.connect_inst(["decode_out[{0}]".format(row),
"clk_bar[{0}]".format(row),
"net[{0}]".format(row),
"vdd", "gnd"])
# add inv2
self.add_inst(name=name_inv2,
mod=self.inv,
offset=inv2_offset,
mirror=inst_mirror)
self.connect_inst(["net[{0}]".format(row),
"wl[{0}]".format(row),
"vdd", "gnd"])
# clk connection
clk_offset= [drc["minwidth_metal1"] + 2 * drc["metal1_to_metal1"],
y_offset + cell_dir.y * self.inv.A_position.y]
self.add_rect(layer="metal1",
offset=clk_offset,
width=self.x_offset0 - 2*drc["metal1_to_metal1"],
height=cell_dir.y *drc["minwidth_metal1"])
# first inv to nand2 B
inv_to_nand2B_offset = [self.x_offset1 - drc["minwidth_metal1"],
y_offset + cell_dir.y * self.NAND2.B_position.y]
self.add_rect(layer="metal1",
offset=inv_to_nand2B_offset,
width=drc["minwidth_metal1"],
height=cell_dir.y*inv_nand2B_connection_height)
# Nand2 out to 2nd inv
nand2_to_2ndinv_offset =[self.x_offset2,
y_offset + cell_dir.y * self.NAND2.Z_position.y]
self.add_rect(layer="metal1",
offset=nand2_to_2ndinv_offset,
width=drc["minwidth_metal1"],
height=cell_dir.y * drc["minwidth_metal1"])
# nand2 A connection
self.add_rect(layer="metal2",
offset=[0, y_offset + cell_dir.y * self.NAND2.A_position.y],
width=self.x_offset1,
height=cell_dir.y*drc["minwidth_metal2"])
self.add_via(layers=("metal1", "via1", "metal2"),
offset=[self.x_offset1,
y_offset + cell_dir.y * self.NAND2.A_position.y],
rotate=m1tm2_rotate,
mirror=m1tm2_mirror)
self.add_via(layers=("metal1", "via1", "metal2"),
offset=[0,
y_offset +cell_dir.y*self.NAND2.A_position.y],
mirror=inst_mirror)
base_offset = vector(self.width, y_offset)
decode_out_offset = base_offset.scale(0,1)+self.NAND2.A_position.scale(cell_dir)
wl_offset = base_offset + self.inv.Z_position.scale(cell_dir)
vdd_offset = base_offset + self.inv.vdd_position.scale(cell_dir)
gnd_offset = base_offset + self.inv.gnd_position.scale(cell_dir)
self.add_label(text="decode_out[{0}]".format(row),
layer="metal2",
offset=decode_out_offset)
self.add_rect(layer="metal1",
offset=wl_offset,
width=drc["minwidth_metal1"]*cell_dir.y,
height=drc["minwidth_metal1"]*cell_dir.y)
self.add_label(text="wl[{0}]".format(row),
layer="metal1",
offset=wl_offset)
self.add_label(text="gnd",
layer="metal1",
offset=gnd_offset)
self.add_label(text="vdd",
layer="metal1",
offset=vdd_offset)
self.decode_out_positions.append(decode_out_offset)
self.WL_positions.append(wl_offset)
self.vdd_positions.append(vdd_offset)
self.gnd_positions.append(gnd_offset)