OpenRAM/compiler/base/hierarchy_layout.py

1394 lines
57 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 collections
import geometry
import gdsMill
import debug
from tech import drc, GDS
from tech import layer as techlayer
from tech import layer_stacks
import os
from globals import OPTS
from vector import vector
from pin_layout import pin_layout
class layout():
"""
Class consisting of a set of objs and instances for a module
This provides a set of useful generic types for hierarchy
management. If a module is a custom designed cell, it will read from
the GDS and spice files and perform LVS/DRC. If it is dynamically
generated, it should implement a constructor to create the
layout/netlist and perform LVS/DRC.
"""
def __init__(self, name):
self.name = name
self.width = None
self.height = None
self.bounding_box = None
self.insts = [] # Holds module/cell layout instances
self.objs = [] # Holds all other objects (labels, geometries, etc)
self.pin_map = {} # Holds name->pin_layout map for all pins
self.visited = [] # List of modules we have already visited
self.is_library_cell = False # Flag for library cells
self.gds_read()
try:
from tech import power_grid
self.pwr_grid_layer = power_grid[0]
except ImportError:
self.pwr_grid_layer = "m3"
############################################################
# GDS layout
############################################################
def offset_all_coordinates(self):
""" This function is called after everything is placed to
shift the origin in the lowest left corner """
offset = self.find_lowest_coords()
self.translate_all(offset)
return offset
def get_gate_offset(self, x_offset, height, inv_num):
"""Gets the base offset and y orientation of stacked rows of gates
assuming a minwidth metal1 vdd/gnd rail. Input is which gate
in the stack from 0..n
"""
if (inv_num % 2 == 0):
base_offset = vector(x_offset, inv_num * height)
y_dir = 1
else:
# we lose a rail after every 2 gates
base_offset = vector(x_offset,
(inv_num + 1) * height - \
(inv_num % 2) * drc["minwidth_m1"])
y_dir = -1
return (base_offset, y_dir)
def find_lowest_coords(self):
"""
Finds the lowest set of 2d cartesian coordinates within
this layout
"""
if len(self.objs) > 0:
lowestx1 = min(obj.lx() for obj in self.objs if obj.name != "label")
lowesty1 = min(obj.by() for obj in self.objs if obj.name != "label")
else:
lowestx1 = lowesty1 = None
if len(self.insts) > 0:
lowestx2 = min(inst.lx() for inst in self.insts)
lowesty2 = min(inst.by() for inst in self.insts)
else:
lowestx2 = lowesty2 = None
if lowestx1 == None and lowestx2 == None:
return None
elif lowestx1 == None:
return vector(lowestx2, lowesty2)
elif lowestx2 == None:
return vector(lowestx1, lowesty1)
else:
return vector(min(lowestx1, lowestx2), min(lowesty1, lowesty2))
def find_highest_coords(self):
"""
Finds the highest set of 2d cartesian coordinates within
this layout
"""
if len(self.objs) > 0:
highestx1 = max(obj.rx() for obj in self.objs if obj.name != "label")
highesty1 = max(obj.uy() for obj in self.objs if obj.name != "label")
else:
highestx1 = highesty1 = None
if len(self.insts) > 0:
highestx2 = max(inst.rx() for inst in self.insts)
highesty2 = max(inst.uy() for inst in self.insts)
else:
highestx2 = highesty2 = None
if highestx1 == None and highestx2 == None:
return None
elif highestx1 == None:
return vector(highestx2, highesty2)
elif highestx2 == None:
return vector(highestx1, highesty1)
else:
return vector(max(highestx1, highestx2),
max(highesty1, highesty2))
def find_highest_layer_coords(self, layer):
"""
Finds the highest set of 2d cartesian coordinates within
this layout on a layer
"""
# Only consider the layer not the purpose for now
layerNumber = techlayer[layer][0]
try:
highestx = max(obj.rx() for obj in self.objs if obj.layerNumber == layerNumber)
except ValueError:
highestx =0
try:
highesty = max(obj.uy() for obj in self.objs if obj.layerNumber == layerNumber)
except ValueError:
highesty = 0
for inst in self.insts:
# This really should be rotated/mirrored etc...
subcoord = inst.mod.find_highest_layer_coords(layer) + inst.offset
highestx = max(highestx, subcoord.x)
highesty = max(highesty, subcoord.y)
return vector(highestx, highesty)
def find_lowest_layer_coords(self, layer):
"""
Finds the highest set of 2d cartesian coordinates within
this layout on a layer
"""
# Only consider the layer not the purpose for now
layerNumber = techlayer[layer][0]
try:
lowestx = min(obj.lx() for obj in self.objs if obj.layerNumber == layerNumber)
except ValueError:
lowestx = 0
try:
lowesty = min(obj.by() for obj in self.objs if obj.layerNumber == layerNumber)
except ValueError:
lowesty = 0
for inst in self.insts:
# This really should be rotated/mirrored etc...
subcoord = inst.mod.find_lowest_layer_coords(layer) + inst.offset
lowestx = min(lowestx, subcoord.x)
lowesty = min(lowesty, subcoord.y)
return vector(lowestx, lowesty)
def translate_all(self, offset):
"""
Translates all objects, instances, and pins by the given (x,y) offset
"""
for obj in self.objs:
obj.offset = vector(obj.offset - offset)
for inst in self.insts:
inst.offset = vector(inst.offset - offset)
# The instances have a precomputed boundary that we need to update.
if inst.__class__.__name__ == "instance":
inst.compute_boundary(inst.offset)
for pin_name in self.pin_map.keys():
# All the pins are absolute coordinates that need to be updated.
pin_list = self.pin_map[pin_name]
for pin in pin_list:
pin.rect = [pin.ll() - offset, pin.ur() - offset]
def add_inst(self, name, mod, offset=[0, 0], mirror="R0", rotate=0):
""" Adds an instance of a mod to this module """
self.insts.append(geometry.instance(name, mod, offset, mirror, rotate))
debug.info(3, "adding instance {}".format(self.insts[-1]))
# This is commented out for runtime reasons
#debug.info(4, "instance list: " + ",".join(x.name for x in self.insts))
return self.insts[-1]
def get_inst(self, name):
""" Retrieve an instance by name """
for inst in self.insts:
if inst.name == name:
return inst
return None
def add_rect(self, layer, offset, width=None, height=None):
"""
Adds a rectangle on a given layer,offset with width and height
"""
if not width:
width = drc["minwidth_{}".format(layer)]
if not height:
height = drc["minwidth_{}".format(layer)]
# negative layers indicate "unused" layers in a given technology
lpp = techlayer[layer]
if lpp[0] >= 0:
self.objs.append(geometry.rectangle(lpp, offset, width, height))
return self.objs[-1]
return None
def add_rect_center(self, layer, offset, width=None, height=None):
"""
Adds a rectangle on a given layer at the center
point with width and height
"""
if not width:
width = drc["minwidth_{}".format(layer)]
if not height:
height = drc["minwidth_{}".format(layer)]
# negative layers indicate "unused" layers in a given technology
lpp = techlayer[layer]
corrected_offset = offset - vector(0.5 * width, 0.5 * height)
if lpp[0] >= 0:
self.objs.append(geometry.rectangle(lpp,
corrected_offset,
width,
height))
return self.objs[-1]
return None
def add_segment_center(self, layer, start, end):
"""
Add a min-width rectanglular segment using center
line on the start to end point
"""
minwidth_layer = drc["minwidth_{}".format(layer)]
if start.x != end.x and start.y != end.y:
debug.error("Nonrectilinear center rect!", -1)
elif start.x != end.x:
offset = vector(0, 0.5 * minwidth_layer)
return self.add_rect(layer,
start-offset,
end.x-start.x,
minwidth_layer)
else:
offset = vector(0.5 * minwidth_layer, 0)
return self.add_rect(layer,
start-offset,
minwidth_layer,
end.y-start.y)
def get_pin(self, text):
"""
Return the pin or list of pins
"""
try:
if len(self.pin_map[text]) > 1:
debug.error("Should use a pin iterator since more than one pin {}".format(text),-1)
# If we have one pin, return it and not the list.
# Otherwise, should use get_pins()
any_pin = next(iter(self.pin_map[text]))
return any_pin
except Exception:
self.gds_write("missing_pin.gds")
debug.error("No pin found with name {0} on {1}. Saved as missing_pin.gds.".format(text,self.name),-1)
def get_pins(self, text):
"""
Return a pin list (instead of a single pin)
"""
if text in self.pin_map.keys():
return self.pin_map[text]
else:
return set()
def get_pin_names(self):
"""
Return a pin list of all pins
"""
return self.pin_map.keys()
def copy_layout_pin(self, instance, pin_name, new_name=""):
"""
Create a copied version of the layout pin at the current level.
You can optionally rename the pin to a new name.
"""
pins = instance.get_pins(pin_name)
debug.check(len(pins) > 0,
"Could not find pin {}".format(pin_name))
for pin in pins:
if new_name == "":
new_name = pin.name
self.add_layout_pin(new_name,
pin.layer,
pin.ll(),
pin.width(),
pin.height())
def copy_layout_pins(self, instance, prefix=""):
"""
Create a copied version of the layout pin at the current level.
You can optionally rename the pin to a new name.
"""
for pin_name in self.pin_map.keys():
self.copy_layout_pin(instance, pin_name, prefix+pin_name)
def add_layout_pin_segment_center(self, text, layer, start, end):
"""
Creates a path like pin with center-line convention
"""
debug.check(start.x == end.x or start.y == end.y,
"Cannot have a non-manhatten layout pin.")
minwidth_layer = drc["minwidth_{}".format(layer)]
# one of these will be zero
width = max(start.x, end.x) - min(start.x, end.x)
height = max(start.y, end.y) - min(start.y, end.y)
ll_offset = vector(min(start.x, end.x), min(start.y, end.y))
# Shift it down 1/2 a width in the 0 dimension
if height == 0:
ll_offset -= vector(0, 0.5 * minwidth_layer)
if width == 0:
ll_offset -= vector(0.5 * minwidth_layer, 0)
# This makes sure it is long enough, but also it is not 0 width!
height = max(minwidth_layer, height)
width = max(minwidth_layer, width)
return self.add_layout_pin(text,
layer,
ll_offset,
width,
height)
def add_layout_pin_rect_center(self, text, layer, offset, width=None, height=None):
""" Creates a path like pin with center-line convention """
if not width:
width = drc["minwidth_{0}".format(layer)]
if not height:
height = drc["minwidth_{0}".format(layer)]
ll_offset = offset - vector(0.5 * width, 0.5 * height)
return self.add_layout_pin(text, layer, ll_offset, width, height)
def remove_layout_pin(self, text):
"""
Delete a labeled pin (or all pins of the same name)
"""
self.pin_map[text] = set()
def add_layout_pin(self, text, layer, offset, width=None, height=None):
"""
Create a labeled pin
"""
if not width:
width = drc["minwidth_{0}".format(layer)]
if not height:
height = drc["minwidth_{0}".format(layer)]
new_pin = pin_layout(text,
[offset, offset+vector(width, height)],
layer)
try:
# Check if there's a duplicate!
# and if so, silently ignore it.
# Rounding errors may result in some duplicates.
if new_pin not in self.pin_map[text]:
self.pin_map[text].add(new_pin)
except KeyError:
self.pin_map[text] = set()
self.pin_map[text].add(new_pin)
return new_pin
def add_label_pin(self, text, layer, offset, width=None, height=None):
"""
Create a labeled pin WITHOUT the pin data structure. This is not an
actual pin but a named net so that we can add a correspondence point
in LVS.
"""
if not width:
width = drc["minwidth_{0}".format(layer)]
if not height:
height = drc["minwidth_{0}".format(layer)]
self.add_rect(layer=layer,
offset=offset,
width=width,
height=height)
self.add_label(text=text,
layer=layer,
offset=offset + vector(0.5 * width,
0.5 * height))
def add_label(self, text, layer, offset=[0, 0], zoom=-1):
"""Adds a text label on the given layer,offset, and zoom level"""
# negative layers indicate "unused" layers in a given technology
debug.info(5, "add label " + str(text) + " " + layer + " " + str(offset))
lpp = techlayer[layer]
if lpp[0] >= 0:
self.objs.append(geometry.label(text, lpp, offset, zoom))
return self.objs[-1]
return None
def add_path(self, layer, coordinates, width=None):
"""Connects a routing path on given layer,coordinates,width."""
debug.info(4, "add path " + str(layer) + " " + str(coordinates))
import wire_path
# NOTE: (UNTESTED) add_path(...) is currently not used
# negative layers indicate "unused" layers in a given technology
# lpp = techlayer[layer]
# if lpp[0] >= 0:
# self.objs.append(geometry.path(lpp, coordinates, width))
wire_path.wire_path(obj=self,
layer=layer,
position_list=coordinates,
width=width)
def add_route(self, layers, coordinates, layer_widths):
"""Connects a routing path on given layer,coordinates,width. The
layers are the (horizontal, via, vertical). add_wire assumes
preferred direction routing whereas this includes layers in
the coordinates.
"""
import route
debug.info(4, "add route " + str(layers) + " " + str(coordinates))
# add an instance of our path that breaks down into rectangles and contacts
route.route(obj=self,
layer_stack=layers,
path=coordinates,
layer_widths=layer_widths)
def add_wire(self, layers, coordinates):
"""Connects a routing path on given layer,coordinates,width.
The layers are the (horizontal, via, vertical). """
import wire
# add an instance of our path that breaks down
# into rectangles and contacts
wire.wire(obj=self,
layer_stack=layers,
position_list=coordinates)
def get_preferred_direction(self, layer):
""" Return the preferred routing directions """
from tech import preferred_directions
return preferred_directions[layer]
def add_via(self, layers, offset, size=[1,1], directions=None, implant_type=None, well_type=None):
""" Add a three layer via structure. """
if not directions:
directions = (self.get_preferred_direction(layers[0]),
self.get_preferred_direction(layers[2]))
from sram_factory import factory
via = factory.create(module_type="contact",
layer_stack=layers,
dimensions=size,
directions=directions,
implant_type=implant_type,
well_type=well_type)
self.add_mod(via)
inst = self.add_inst(name=via.name,
mod=via,
offset=offset)
# We don't model the logical connectivity of wires/paths
self.connect_inst([])
return inst
def add_via_center(self, layers, offset, directions=None, size=[1,1], implant_type=None, well_type=None):
"""
Add a three layer via structure by the center coordinate
accounting for mirroring and rotation.
"""
if not directions:
directions = (self.get_preferred_direction(layers[0]),
self.get_preferred_direction(layers[2]))
from sram_factory import factory
via = factory.create(module_type="contact",
layer_stack=layers,
dimensions=size,
directions=directions,
implant_type=implant_type,
well_type=well_type)
height = via.height
width = via.width
corrected_offset = offset + vector(-0.5 * width,
-0.5 * height)
self.add_mod(via)
inst = self.add_inst(name=via.name,
mod=via,
offset=corrected_offset)
# We don't model the logical connectivity of wires/paths
self.connect_inst([])
return inst
def add_via_stack(self, offset, direction, from_layer, to_layer,
size=[1,1]):
"""
Punch a stack of vias from a start layer to a target layer.
"""
return self.__add_via_stack_internal(offset=offset,
direction=direction,
from_layer=from_layer,
to_layer=to_layer,
via_func=self.add_via,
last_via=None,
size=size)
def add_via_stack_center(self, offset, direction, from_layer, to_layer,
size=[1,1]):
"""
Punch a stack of vias from a start layer to a target layer by the center
coordinate accounting for mirroring and rotation.
"""
return self.__add_via_stack_internal(offset=offset,
direction=direction,
from_layer=from_layer,
to_layer=to_layer,
via_func=self.add_via_center,
last_via=None,
size=size)
def __add_via_stack_internal(self, offset, direction, from_layer, to_layer,
via_func, last_via, size):
"""
Punch a stack of vias from a start layer to a target layer. Here we
figure out whether to punch it up or down the stack.
"""
if from_layer == to_layer:
return last_via
from_id = int(from_layer[1])
to_id = int(to_layer[1])
if from_id < to_id: # grow the stack up
search_id = 0
next_id = 2
else: # grow the stack down
search_id = 2
next_id = 0
curr_stack = next(filter(lambda stack: stack[search_id] == from_layer, layer_stacks), None)
if curr_stack is None:
raise ValueError("Cannot create via from '{0}' to '{1}'." \
"Layer '{0}' not defined"
.format(from_layer, to_layer))
via = via_func(layers=curr_stack, size=size, offset=offset, directions=direction)
return self.__add_via_stack_internal(offset=offset,
direction=direction,
from_layer=curr_stack[next_id],
to_layer=to_layer,
via_func=via_func,
last_via=via,
size=size)
def add_ptx(self, offset, mirror="R0", rotate=0, width=1, mults=1, tx_type="nmos"):
"""Adds a ptx module to the design."""
import ptx
mos = ptx.ptx(width=width,
mults=mults,
tx_type=tx_type)
self.add_mod(mos)
inst = self.add_inst(name=mos.name,
mod=mos,
offset=offset,
mirror=mirror,
rotate=rotate)
return inst
def gds_read(self):
"""Reads a GDSII file in the library and checks if it exists
Otherwise, start a new layout for dynamic generation."""
# This must be done for netlist only mode too
if os.path.isfile(self.gds_file):
self.is_library_cell = True
if OPTS.netlist_only:
self.gds = None
return
# open the gds file if it exists or else create a blank layout
if os.path.isfile(self.gds_file):
debug.info(3, "opening {}".format(self.gds_file))
self.gds = gdsMill.VlsiLayout(units=GDS["unit"])
reader = gdsMill.Gds2reader(self.gds)
reader.loadFromFile(self.gds_file)
else:
debug.info(3, "Creating layout structure {}".format(self.name))
self.gds = gdsMill.VlsiLayout(name=self.name, units=GDS["unit"])
def print_gds(self, gds_file=None):
"""Print the gds file (not the vlsi class) to the terminal """
if not gds_file:
gds_file = self.gds_file
debug.info(4, "Printing {}".format(gds_file))
arrayCellLayout = gdsMill.VlsiLayout(units=GDS["unit"])
reader = gdsMill.Gds2reader(arrayCellLayout, debugToTerminal=1)
reader.loadFromFile(gds_file)
def clear_visited(self):
""" Recursively clear the visited flag """
self.visited = []
def gds_write_file(self, gds_layout):
"""Recursive GDS write function"""
# Visited means that we already prepared self.gds for this subtree
if self.name in self.visited:
return
for i in self.insts:
i.gds_write_file(gds_layout)
for i in self.objs:
i.gds_write_file(gds_layout)
for pin_name in self.pin_map.keys():
for pin in self.pin_map[pin_name]:
pin.gds_write_file(gds_layout)
# If it's not a premade cell
# and we didn't add our own boundary,
# we should add a boundary just for DRC in some technologies
if not self.is_library_cell and not self.bounding_box:
# If there is a boundary layer, and we didn't create one, add one.
if "stdc" in techlayer.keys():
boundary_layer = "stdc"
boundary = [self.find_lowest_coords(),
self.find_highest_coords()]
height = boundary[1][1] - boundary[0][1]
width = boundary[1][0] - boundary[0][0]
(layer_number, layer_purpose) = techlayer[boundary_layer]
gds_layout.addBox(layerNumber=layer_number,
purposeNumber=layer_purpose,
offsetInMicrons=boundary[0],
width=width,
height=height,
center=False)
debug.info(2, "Adding {0} boundary {1}".format(self.name, boundary))
self.visited.append(self.name)
def gds_write(self, gds_name):
"""Write the entire gds of the object to the file."""
debug.info(3, "Writing to {}".format(gds_name))
# If we already wrote a GDS, we need to reset and traverse it again in
# case we made changes.
if not self.is_library_cell and self.visited:
debug.info(3, "Creating layout structure {}".format(self.name))
self.gds = gdsMill.VlsiLayout(name=self.name, units=GDS["unit"])
writer = gdsMill.Gds2writer(self.gds)
# MRG: 3/2/18 We don't want to clear the visited flag since
# this would result in duplicates of all instances being placed in self.gds
# which may have been previously processed!
# MRG: 10/4/18 We need to clear if we make changes and write a second GDS!
self.clear_visited()
# recursively create all the remaining objects
self.gds_write_file(self.gds)
# populates the xyTree data structure for gds
# self.gds.prepareForWrite()
writer.writeToFile(gds_name)
debug.info(3, "Done writing to {}".format(gds_name))
def get_boundary(self):
""" Return the lower-left and upper-right coordinates of boundary """
# This assumes nothing spans outside of the width and height!
return [vector(0, 0), vector(self.width, self.height)]
#return [self.find_lowest_coords(), self.find_highest_coords()]
def get_blockages(self, layer, top_level=False):
"""
Write all of the obstacles in the current (and children)
modules to the lef file.
Do not write the pins since they aren't obstructions.
"""
if type(layer) == str:
lpp = techlayer[layer]
else:
lpp = layer
blockages = []
for i in self.objs:
blockages += i.get_blockages(lpp)
for i in self.insts:
blockages += i.get_blockages(lpp)
# Must add pin blockages to non-top cells
if not top_level:
blockages += self.get_pin_blockages(lpp)
return blockages
def get_pin_blockages(self, lpp):
""" Return the pin shapes as blockages for non-top-level blocks. """
# FIXME: We don't have a body contact in ptx, so just ignore it for now
import copy
pin_names = copy.deepcopy(self.pins)
if self.name.startswith("pmos") or self.name.startswith("nmos"):
pin_names.remove("B")
blockages = []
for pin_name in pin_names:
pin_list = self.get_pins(pin_name)
for pin in pin_list:
if pin.same_lpp(pin.lpp, lpp):
blockages += [pin.rect]
return blockages
def create_horizontal_pin_bus(self, layer, pitch, offset, names, length):
""" Create a horizontal bus of pins. """
return self.create_bus(layer,
pitch,
offset,
names,
length,
vertical=False,
make_pins=True)
def create_vertical_pin_bus(self, layer, pitch, offset, names, length):
""" Create a horizontal bus of pins. """
return self.create_bus(layer,
pitch,
offset,
names,
length,
vertical=True,
make_pins=True)
def create_vertical_bus(self, layer, pitch, offset, names, length):
""" Create a horizontal bus. """
return self.create_bus(layer,
pitch,
offset,
names,
length,
vertical=True,
make_pins=False)
def create_horizontal_bus(self, layer, pitch, offset, names, length):
""" Create a horizontal bus. """
return self.create_bus(layer,
pitch,
offset,
names,
length,
vertical=False,
make_pins=False)
def create_bus(self, layer, pitch, offset, names, length, vertical, make_pins):
"""
Create a horizontal or vertical bus. It can be either just rectangles, or actual
layout pins. It returns an map of line center line positions indexed by name.
The other coordinate is a 0 since the bus provides a range.
TODO: combine with channel router.
"""
# half minwidth so we can return the center line offsets
half_minwidth = 0.5 * drc["minwidth_{}".format(layer)]
line_positions = {}
if vertical:
for i in range(len(names)):
line_offset = offset + vector(i * pitch, 0)
if make_pins:
self.add_layout_pin(text=names[i],
layer=layer,
offset=line_offset,
height=length)
else:
self.add_rect(layer=layer,
offset=line_offset,
height=length)
# Make this the center of the rail
line_positions[names[i]] = line_offset + vector(half_minwidth,
0.5 * length)
else:
for i in range(len(names)):
line_offset = offset + vector(0,
i * pitch + half_minwidth)
if make_pins:
self.add_layout_pin(text=names[i],
layer=layer,
offset=line_offset,
width=length)
else:
self.add_rect(layer=layer,
offset=line_offset,
width=length)
# Make this the center of the rail
line_positions[names[i]] = line_offset + vector(0.5 * length,
half_minwidth)
return line_positions
def connect_horizontal_bus(self, mapping, inst, bus_offsets,
layer_stack=("m1", "via1", "m2")):
""" Horizontal version of connect_bus. """
self.connect_bus(mapping, inst, bus_offsets, layer_stack, True)
def connect_vertical_bus(self, mapping, inst, bus_offsets,
layer_stack=("m1", "via1", "m2")):
""" Vertical version of connect_bus. """
self.connect_bus(mapping, inst, bus_offsets, layer_stack, False)
def connect_bus(self, mapping, inst, bus_offsets, layer_stack, horizontal):
"""
Connect a mapping of pin -> name for a bus. This could be
replaced with a channel router in the future.
NOTE: This has only really been tested with point-to-point
connections (not multiple pins on a net).
"""
(horizontal_layer, via_layer, vertical_layer) = layer_stack
if horizontal:
route_layer = vertical_layer
else:
route_layer = horizontal_layer
for (pin_name, bus_name) in mapping:
pin = inst.get_pin(pin_name)
pin_pos = pin.center()
bus_pos = bus_offsets[bus_name]
if horizontal:
# up/down then left/right
mid_pos = vector(pin_pos.x, bus_pos.y)
else:
# left/right then up/down
mid_pos = vector(bus_pos.x, pin_pos.y)
self.add_wire(layer_stack,
[bus_pos, mid_pos, pin_pos])
# Connect to the pin on the instances with a via if it is
# not on the right layer
if pin.layer != route_layer:
self.add_via_center(layers=layer_stack,
offset=pin_pos)
# FIXME: output pins tend to not be rotate,
# but supply pins are. Make consistent?
# We only need a via if they happened to align perfectly
# so the add_wire didn't add a via
if (horizontal and bus_pos.y == pin_pos.y) or (not horizontal and bus_pos.x == pin_pos.x):
self.add_via_center(layers=layer_stack,
offset=bus_pos,
rotate=90)
def get_layer_pitch(self, layer):
""" Return the track pitch on a given layer """
if layer == "m1":
return (self.m1_pitch,
self.m1_pitch - self.m1_space,
self.m1_space)
elif layer == "m2":
return (self.m2_pitch,
self.m2_pitch - self.m2_space,
self.m2_space)
elif layer == "m3":
return (self.m3_pitch,
self.m3_pitch - self.m3_space,
self.m3_space)
elif layer == "m4":
from tech import layer as tech_layer
if "m4" in tech_layer:
return (self.m3_pitch,
self.m3_pitch - self.m4_space,
self.m4_space)
else:
return (self.m3_pitch,
self.m3_pitch - self.m3_space,
self.m3_space)
else:
debug.error("Cannot find layer pitch.")
def add_horizontal_trunk_route(self,
pins,
trunk_offset,
layer_stack,
pitch):
"""
Create a trunk route for all pins with
the trunk located at the given y offset.
"""
max_x = max([pin.center().x for pin in pins])
min_x = min([pin.center().x for pin in pins])
# if we are less than a pitch, just create a non-preferred layer jog
if max_x-min_x <= pitch:
half_layer_width = 0.5 * drc["minwidth_{0}".format(self.vertical_layer)]
# Add the horizontal trunk on the vertical layer!
self.add_path(self.vertical_layer,
[vector(min_x - half_layer_width, trunk_offset.y),
vector(max_x + half_layer_width, trunk_offset.y)])
# Route each pin to the trunk
for pin in pins:
# No bend needed here
mid = vector(pin.center().x, trunk_offset.y)
self.add_path(self.vertical_layer, [pin.center(), mid])
else:
# Add the horizontal trunk
self.add_path(self.horizontal_layer,
[vector(min_x, trunk_offset.y),
vector(max_x, trunk_offset.y)])
# Route each pin to the trunk
for pin in pins:
mid = vector(pin.center().x, trunk_offset.y)
self.add_path(self.vertical_layer, [pin.center(), mid])
self.add_via_center(layers=layer_stack,
offset=mid)
def add_vertical_trunk_route(self,
pins,
trunk_offset,
layer_stack,
pitch):
"""
Create a trunk route for all pins with the
trunk located at the given x offset.
"""
max_y = max([pin.center().y for pin in pins])
min_y = min([pin.center().y for pin in pins])
# if we are less than a pitch, just create a non-preferred layer jog
if max_y-min_y <= pitch:
half_layer_width = 0.5 * drc["minwidth_{0}".format(self.horizontal_layer)]
# Add the vertical trunk on the horizontal layer!
self.add_path(self.horizontal_layer,
[vector(trunk_offset.x, min_y - half_layer_width),
vector(trunk_offset.x,max_y + half_layer_width)])
# Route each pin to the trunk
for pin in pins:
# No bend needed here
mid = vector(trunk_offset.x, pin.center().y)
self.add_path(self.horizontal_layer, [pin.center(), mid])
else:
# Add the vertical trunk
self.add_path(self.vertical_layer,
[vector(trunk_offset.x, min_y),
vector(trunk_offset.x, max_y)])
# Route each pin to the trunk
for pin in pins:
mid = vector(trunk_offset.x, pin.center().y)
self.add_path(self.horizontal_layer, [pin.center(), mid])
self.add_via_center(layers=layer_stack,
offset=mid)
def create_channel_route(self, netlist,
offset,
layer_stack,
vertical=False):
"""
The net list is a list of the nets. Each net is a list of pins
to be connected. Offset is the lower-left of where the
routing channel will start. This does NOT try to minimize the
number of tracks -- instead, it picks an order to avoid the
vertical conflicts between pins.
"""
def remove_net_from_graph(pin, g):
"""
Remove the pin from the graph and all conflicts
"""
g.pop(pin, None)
# Remove the pin from all conflicts
# FIXME: This is O(n^2), so maybe optimize it.
for other_pin,conflicts in g.items():
if pin in conflicts:
conflicts.remove(pin)
g[other_pin]=conflicts
return g
def vcg_nets_overlap(net1, net2, vertical, pitch):
"""
Check all the pin pairs on two nets and return a pin
overlap if any pin overlaps.
"""
for pin1 in net1:
for pin2 in net2:
if vcg_pin_overlap(pin1, pin2, vertical, pitch):
return True
return False
def vcg_pin_overlap(pin1, pin2, vertical, pitch):
""" Check for vertical or horizontal overlap of the two pins """
# FIXME: If the pins are not in a row, this may break.
# However, a top pin shouldn't overlap another top pin,
# for example, so the
# extra comparison *shouldn't* matter.
# Pin 1 must be in the "BOTTOM" set
x_overlap = pin1.by() < pin2.by() and abs(pin1.center().x-pin2.center().x)<pitch
# Pin 1 must be in the "LEFT" set
y_overlap = pin1.lx() < pin2.lx() and abs(pin1.center().y-pin2.center().y)<pitch
overlaps = (not vertical and x_overlap) or (vertical and y_overlap)
return overlaps
if self.get_preferred_direction(layer_stack[0]) == "V":
self.vertical_layer = layer_stack[0]
self.horizontal_layer = layer_stack[2]
else:
self.vertical_layer = layer_stack[2]
self.horizontal_layer = layer_stack[0]
layer_stuff = self.get_layer_pitch(self.vertical_layer)
(self.vertical_pitch, self.vertical_width, self.vertical_space) = layer_stuff
layer_stuff = self.get_layer_pitch(self.horizontal_layer)
(self.horizontal_pitch, self.horizontal_width, self.horizontal_space) = layer_stuff
# FIXME: Must extend this to a horizontal conflict graph
# too if we want to minimize the
# number of tracks!
# hcg = {}
# Initialize the vertical conflict graph (vcg)
# and make a list of all pins
vcg = collections.OrderedDict()
# Create names for the nets for the graphs
nets = collections.OrderedDict()
index = 0
# print(netlist)
for pin_list in netlist:
net_name = "n{}".format(index)
index += 1
nets[net_name] = pin_list
# Find the vertical pin conflicts
# FIXME: O(n^2) but who cares for now
for net_name1 in nets:
if net_name1 not in vcg.keys():
vcg[net_name1] = []
for net_name2 in nets:
if net_name2 not in vcg.keys():
vcg[net_name2] = []
# Skip yourself
if net_name1 == net_name2:
continue
if vertical and vcg_nets_overlap(nets[net_name1],
nets[net_name2],
vertical,
self.vertical_pitch):
vcg[net_name2].append(net_name1)
elif not vertical and vcg_nets_overlap(nets[net_name1],
nets[net_name2],
vertical,
self.horizontal_pitch):
vcg[net_name2].append(net_name1)
# list of routes to do
while vcg:
# from pprint import pformat
# print("VCG:\n",pformat(vcg))
# get a route from conflict graph with empty fanout set
net_name = None
for net_name, conflicts in vcg.items():
if len(conflicts) == 0:
vcg = remove_net_from_graph(net_name, vcg)
break
else:
# FIXME: We don't support cyclic VCGs right now.
debug.error("Cyclic VCG in channel router.", -1)
# These are the pins we'll have to connect
pin_list = nets[net_name]
# print("Routing:", net_name, [x.name for x in pin_list])
# Remove the net from other constriants in the VCG
vcg = remove_net_from_graph(net_name, vcg)
# Add the trunk routes from the bottom up for
# horizontal or the left to right for vertical
if vertical:
self.add_vertical_trunk_route(pin_list,
offset,
layer_stack,
self.vertical_pitch)
offset += vector(self.vertical_pitch, 0)
else:
self.add_horizontal_trunk_route(pin_list,
offset,
layer_stack,
self.horizontal_pitch)
offset += vector(0, self.horizontal_pitch)
def create_vertical_channel_route(self, netlist, offset, layer_stack):
"""
Wrapper to create a vertical channel route
"""
self.create_channel_route(netlist, offset, layer_stack, vertical=True)
def create_horizontal_channel_route(self, netlist, offset, layer_stack):
"""
Wrapper to create a horizontal channel route
"""
self.create_channel_route(netlist, offset, layer_stack, vertical=False)
def add_boundary(self, ll=vector(0, 0), ur=None):
""" Add boundary for debugging dimensions """
if OPTS.netlist_only:
return
if "stdc" in techlayer.keys():
boundary_layer = "stdc"
else:
boundary_layer = "boundary"
if not ur:
self.bounding_box = self.add_rect(layer=boundary_layer,
offset=ll,
height=self.height,
width=self.width)
else:
self.bounding_box = self.add_rect(layer=boundary_layer,
offset=ll,
height=ur.y-ll.y,
width=ur.x-ll.x)
def add_enclosure(self, insts, layer="nwell"):
""" Add a layer that surrounds the given instances. Useful
for creating wells, for example. Doesn't check for minimum widths or
spacings."""
xmin = insts[0].lx()
ymin = insts[0].by()
xmax = insts[0].rx()
ymax = insts[0].uy()
for inst in insts:
xmin = min(xmin, inst.lx())
ymin = min(ymin, inst.by())
xmax = max(xmax, inst.rx())
ymax = max(ymax, inst.uy())
self.add_rect(layer=layer,
offset=vector(xmin, ymin),
width=xmax-xmin,
height=ymax-ymin)
def copy_power_pins(self, inst, name):
"""
This will copy a power pin if it is on the lowest power_grid layer.
If it is on M1, it will add a power via too.
"""
pins = inst.get_pins(name)
for pin in pins:
if pin.layer == self.pwr_grid_layer:
self.add_layout_pin(name,
pin.layer,
pin.ll(),
pin.width(),
pin.height())
elif pin.layer == "m1":
self.add_power_pin(name, pin.center())
else:
debug.warning("{0} pins of {1} should be on {2} or metal1 for "\
"supply router."
.format(name,inst.name,self.pwr_grid_layer))
def add_power_pin(self, name, loc, size=[1, 1], vertical=False, start_layer="m1"):
"""
Add a single power pin from the lowest power_grid layer down to M1 at
the given center location. The starting layer is specified to determine
which vias are needed.
"""
if vertical:
direction = ("V", "V")
else:
direction = ("H", "H")
via = self.add_via_stack_center(from_layer=start_layer,
to_layer=self.pwr_grid_layer,
size=size,
offset=loc,
direction=direction)
if start_layer == self.pwr_grid_layer:
self.add_layout_pin_rect_center(text=name,
layer=self.pwr_grid_layer,
offset=loc)
else:
self.add_layout_pin_rect_center(text=name,
layer=self.pwr_grid_layer,
offset=loc,
width=via.width,
height=via.height)
def add_power_ring(self, bbox):
"""
Create vdd and gnd power rings around an area of the bounding box
argument. Must have a supply_rail_width and supply_rail_pitch
defined as a member variable. Defines local variables of the
left/right/top/bottom vdd/gnd center offsets for use in other
modules..
"""
[ll, ur] = bbox
supply_rail_spacing = self.supply_rail_pitch - self.supply_rail_width
height = (ur.y-ll.y) + 3 * self.supply_rail_pitch - supply_rail_spacing
width = (ur.x-ll.x) + 3 * self.supply_rail_pitch - supply_rail_spacing
# LEFT vertical rails
offset = ll + vector(-2 * self.supply_rail_pitch,
-2 * self.supply_rail_pitch)
left_gnd_pin = self.add_layout_pin(text="gnd",
layer="m2",
offset=offset,
width=self.supply_rail_width,
height=height)
offset = ll + vector(-1 * self.supply_rail_pitch,
-1 * self.supply_rail_pitch)
left_vdd_pin = self.add_layout_pin(text="vdd",
layer="m2",
offset=offset,
width=self.supply_rail_width,
height=height)
# RIGHT vertical rails
offset = vector(ur.x, ll.y) + vector(0, -2 * self.supply_rail_pitch)
right_gnd_pin = self.add_layout_pin(text="gnd",
layer="m2",
offset=offset,
width=self.supply_rail_width,
height=height)
offset = vector(ur.x, ll.y) + vector(self.supply_rail_pitch,
-1 * self.supply_rail_pitch)
right_vdd_pin = self.add_layout_pin(text="vdd",
layer="m2",
offset=offset,
width=self.supply_rail_width,
height=height)
# BOTTOM horizontal rails
offset = ll + vector(-2 * self.supply_rail_pitch,
-2 * self.supply_rail_pitch)
bottom_gnd_pin = self.add_layout_pin(text="gnd",
layer="m1",
offset=offset,
width=width,
height=self.supply_rail_width)
offset = ll + vector(-1 * self.supply_rail_pitch,
-1 * self.supply_rail_pitch)
bottom_vdd_pin = self.add_layout_pin(text="vdd",
layer="m1",
offset=offset,
width=width,
height=self.supply_rail_width)
# TOP horizontal rails
offset = vector(ll.x, ur.y) + vector(-2 * self.supply_rail_pitch,
0)
top_gnd_pin = self.add_layout_pin(text="gnd",
layer="m1",
offset=offset,
width=width,
height=self.supply_rail_width)
offset = vector(ll.x, ur.y) + vector(-1 * self.supply_rail_pitch,
self.supply_rail_pitch)
top_vdd_pin = self.add_layout_pin(text="vdd",
layer="m1",
offset=offset,
width=width,
height=self.supply_rail_width)
# Remember these for connecting things in the design
self.left_gnd_x_center = left_gnd_pin.cx()
self.left_vdd_x_center = left_vdd_pin.cx()
self.right_gnd_x_center = right_gnd_pin.cx()
self.right_vdd_x_center = right_vdd_pin.cx()
self.bottom_gnd_y_center = bottom_gnd_pin.cy()
self.bottom_vdd_y_center = bottom_vdd_pin.cy()
self.top_gnd_y_center = top_gnd_pin.cy()
self.top_vdd_y_center = top_vdd_pin.cy()
# Find the number of vias for this pitch
self.supply_vias = 1
from sram_factory import factory
while True:
c = factory.create(module_type="contact",
layer_stack=self.m1_stack,
dimensions=(self.supply_vias, self.supply_vias))
if c.second_layer_width < self.supply_rail_width and c.second_layer_height < self.supply_rail_width:
self.supply_vias += 1
else:
self.supply_vias -= 1
break
via_points = [vector(self.left_gnd_x_center, self.bottom_gnd_y_center),
vector(self.left_gnd_x_center, self.top_gnd_y_center),
vector(self.right_gnd_x_center, self.bottom_gnd_y_center),
vector(self.right_gnd_x_center, self.top_gnd_y_center),
vector(self.left_vdd_x_center, self.bottom_vdd_y_center),
vector(self.left_vdd_x_center, self.top_vdd_y_center),
vector(self.right_vdd_x_center, self.bottom_vdd_y_center),
vector(self.right_vdd_x_center, self.top_vdd_y_center)]
for pt in via_points:
self.add_via_center(layers=self.m1_stack,
offset=pt,
size=(self.supply_vias,
self.supply_vias))
def pdf_write(self, pdf_name):
"""
Display the layout to a PDF file.
"""
debug.error("NOTE: Currently does not work (Needs further research)")
# self.pdf_name = self.name + ".pdf"
debug.info(0, "Writing to {}".format(pdf_name))
pdf = gdsMill.pdfLayout(self.gds)
return
pdf.layerColors[self.gds.layerNumbersInUse[0]] = "#219E1C"
pdf.layerColors[self.gds.layerNumbersInUse[1]] = "#271C9E"
pdf.layerColors[self.gds.layerNumbersInUse[2]] = "#CC54C8"
pdf.layerColors[self.gds.layerNumbersInUse[3]] = "#E9C514"
pdf.layerColors[self.gds.layerNumbersInUse[4]] = "#856F00"
pdf.layerColors[self.gds.layerNumbersInUse[5]] = "#BD1444"
pdf.layerColors[self.gds.layerNumbersInUse[6]] = "#FD1444"
pdf.layerColors[self.gds.layerNumbersInUse[7]] = "#FD1414"
pdf.setScale(500)
pdf.drawLayout()
pdf.writeToFile(pdf_name)
def print_attr(self):
"""Prints a list of attributes for the current layout object"""
debug.info(0,
"|==============================================================================|")
debug.info(0,
"|========= LIST OF OBJECTS (Rects) FOR: " + self.name)
debug.info(0,
"|==============================================================================|")
for obj in self.objs:
debug.info(0, "layer={0} : offset={1} : size={2}".format(obj.layerNumber,
obj.offset,
obj.size))
debug.info(0,
"|==============================================================================|")
debug.info(0,
"|========= LIST OF INSTANCES FOR: " + self.name)
debug.info(0,
"|==============================================================================|")
for inst in self.insts:
debug.info(0, "name={0} : mod={1} : offset={2}".format(inst.name,
inst.mod.name,
inst.offset))