OpenRAM/compiler/router/signal_router.py

217 lines
7.2 KiB
Python
Raw Normal View History

import gdsMill
import tech
from contact import contact
import math
import debug
from pin_layout import pin_layout
from vector import vector
from vector3d import vector3d
from globals import OPTS
from router import router
class signal_router(router):
"""A router class to read an obstruction map from a gds and plan a
route on a given layer. This is limited to two layer routes.
"""
def __init__(self, gds_name):
"""Use the gds file for the blockages with the top module topName and
layers for the layers to route on
"""
router.__init__(self, gds_name)
# all the paths we've routed so far (to supplement the blockages)
self.paths = []
def create_routing_grid(self):
"""
Create a routing grid that spans given area. Wires cannot exist outside region.
"""
# We will add a halo around the boundary
# of this many tracks
size = self.ur - self.ll
debug.info(1,"Size: {0} x {1}".format(size.x,size.y))
import astar_grid
self.rg = astar_grid.astar_grid()
def route(self, cell, layers, src, dest, detour_scale=5):
"""
Route a single source-destination net and return
the simplified rectilinear path. Cost factor is how sub-optimal to explore for a feasible route.
This is used to speed up the routing when there is not much detouring needed.
"""
self.cell = cell
# Clear the pins if we have previously routed
if (hasattr(self,'rg')):
self.clear_pins()
else:
# Set up layers and track sizes
self.set_layers(layers)
# Creat a routing grid over the entire area
# FIXME: This could be created only over the routing region,
# but this is simplest for now.
self.create_routing_grid()
# This will get all shapes as blockages
self.find_blockages()
# Get the pin shapes
self.get_pin(src)
self.get_pin(dest)
# Now add the blockages (all shapes except the src/tgt pins)
self.add_blockages()
# Add blockages from previous paths
self.add_path_blockages()
# Now add the src/tgt if they are not blocked by other shapes
self.add_pin(src,True)
self.add_pin(dest,False)
# returns the path in tracks
(path,cost) = self.rg.astar_route(detour_scale)
if path:
debug.info(1,"Found path: cost={0} ".format(cost))
debug.info(2,str(path))
self.add_route(path)
return True
else:
self.write_debug_gds()
# clean up so we can try a reroute
self.clear_pins()
return False
def add_route(self,path):
"""
Add the current wire route to the given design instance.
"""
debug.info(3,"Set path: " + str(path))
# Keep track of path for future blockages
self.paths.append(path)
# This is marked for debug
self.rg.add_path(path)
# For debugging... if the path failed to route.
if False or path==None:
self.write_debug_gds()
# First, simplify the path for
#debug.info(1,str(self.path))
contracted_path = self.contract_path(path)
debug.info(1,str(contracted_path))
# convert the path back to absolute units from tracks
abs_path = map(self.convert_point_to_units,contracted_path)
debug.info(1,str(abs_path))
self.cell.add_route(self.layers,abs_path)
def get_inertia(self,p0,p1):
"""
Sets the direction based on the previous direction we came from.
"""
# direction (index) of movement
if p0.x!=p1.x:
return 0
elif p0.y!=p1.y:
return 1
else:
# z direction
return 2
def contract_path(self,path):
"""
Remove intermediate points in a rectilinear path.
"""
newpath = [path[0]]
for i in range(1,len(path)-1):
prev_inertia=self.get_inertia(path[i-1],path[i])
next_inertia=self.get_inertia(path[i],path[i+1])
# if we switch directions, add the point, otherwise don't
if prev_inertia!=next_inertia:
newpath.append(path[i])
# always add the last path
newpath.append(path[-1])
return newpath
def add_path_blockages(self):
"""
Go through all of the past paths and add them as blockages.
This is so we don't have to write/reload the GDS.
"""
for path in self.paths:
for grid in path:
self.rg.set_blocked(grid)
def write_debug_gds(self):
"""
Write out a GDS file with the routing grid and search information annotated on it.
"""
# Only add the debug info to the gds file if we have any debugging on.
# This is because we may reroute a wire with detours and don't want the debug information.
if OPTS.debug_level==0: return
self.add_router_info()
pin_names = list(self.pins.keys())
debug.error("Writing debug_route.gds from {0} to {1}".format(self.source_pin_name,self.target_pin_name))
self.cell.gds_write("debug_route.gds")
def add_router_info(self):
"""
Write the routing grid and router cost, blockage, pins on
the boundary layer for debugging purposes. This can only be
called once or the labels will overlap.
"""
debug.info(0,"Adding router info for {0} to {1}".format(self.source_pin_name,self.target_pin_name))
grid_keys=self.rg.map.keys()
partial_track=vector(0,self.track_width/6.0)
for g in grid_keys:
shape = self.convert_full_track_to_shape(g)
self.cell.add_rect(layer="boundary",
offset=shape[0],
width=shape[1].x-shape[0].x,
height=shape[1].y-shape[0].y)
# These are the on grid pins
#rect = self.convert_track_to_pin(g)
#self.cell.add_rect(layer="boundary",
# offset=rect[0],
# width=rect[1].x-rect[0].x,
# height=rect[1].y-rect[0].y)
t=self.rg.map[g].get_type()
# midpoint offset
off=vector((shape[1].x+shape[0].x)/2,
(shape[1].y+shape[0].y)/2)
if g[2]==1:
# Upper layer is upper right label
type_off=off+partial_track
else:
# Lower layer is lower left label
type_off=off-partial_track
if t!=None:
self.cell.add_label(text=str(t),
layer="text",
offset=type_off)
self.cell.add_label(text="{0},{1}".format(g[0],g[1]),
layer="text",
offset=shape[0],
zoom=0.05)