mirror of https://github.com/VLSIDA/OpenRAM.git
164 lines
4.9 KiB
Python
164 lines
4.9 KiB
Python
import gdsMill
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import tech
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from contact import contact
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import math
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import debug
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from pin_layout import pin_layout
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from vector import vector
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from vector3d import vector3d
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from globals import OPTS
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from router import router
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class signal_router(router):
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"""A router class to read an obstruction map from a gds and plan a
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route on a given layer. This is limited to two layer routes.
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"""
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def __init__(self, gds_name=None, module=None):
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"""Use the gds file for the blockages with the top module topName and
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layers for the layers to route on
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"""
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router.__init__(self, gds_name, module)
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# all the paths we've routed so far (to supplement the blockages)
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self.paths = []
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def create_routing_grid(self):
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"""
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Create a sprase routing grid with A* expansion functions.
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"""
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# We will add a halo around the boundary
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# of this many tracks
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size = self.ur - self.ll
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debug.info(1,"Size: {0} x {1}".format(size.x,size.y))
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import astar_grid
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self.rg = astar_grid.astar_grid()
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def route(self, cell, layers, src, dest, detour_scale=5):
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"""
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Route a single source-destination net and return
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the simplified rectilinear path. Cost factor is how sub-optimal to explore for a feasible route.
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This is used to speed up the routing when there is not much detouring needed.
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"""
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debug.info(1,"Running signal router from {0} to {1}...".format(src,dest))
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self.cell = cell
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self.source_pin_name = src
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self.target_pin_name = dest
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# Clear the pins if we have previously routed
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if (hasattr(self,'rg')):
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self.clear_pins()
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else:
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# Set up layers and track sizes
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self.set_layers(layers)
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# Creat a routing grid over the entire area
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# FIXME: This could be created only over the routing region,
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# but this is simplest for now.
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self.create_routing_grid()
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# This will get all shapes as blockages
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self.find_blockages()
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# Get the pin shapes
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self.get_pin(src)
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self.get_pin(dest)
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# Now add the blockages (all shapes except the src/tgt pins)
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self.add_blockages()
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# Add blockages from previous paths
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self.add_path_blockages()
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# Now add the src/tgt if they are not blocked by other shapes
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self.add_pin(src,True)
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self.add_pin(dest,False)
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# returns the path in tracks
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(path,cost) = self.rg.route(detour_scale)
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if path:
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debug.info(1,"Found path: cost={0} ".format(cost))
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debug.info(2,str(path))
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self.add_route(path)
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return True
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else:
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self.write_debug_gds()
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# clean up so we can try a reroute
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self.clear_pins()
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return False
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def add_route(self,path):
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"""
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Add the current wire route to the given design instance.
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"""
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debug.info(3,"Set path: " + str(path))
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# Keep track of path for future blockages
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self.paths.append(path)
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# This is marked for debug
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self.rg.add_path(path)
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# For debugging... if the path failed to route.
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if False or path==None:
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self.write_debug_gds()
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# First, simplify the path for
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#debug.info(1,str(self.path))
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contracted_path = self.contract_path(path)
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debug.info(1,str(contracted_path))
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# convert the path back to absolute units from tracks
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abs_path = map(self.convert_point_to_units,contracted_path)
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debug.info(1,str(abs_path))
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self.cell.add_route(self.layers,abs_path)
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def get_inertia(self,p0,p1):
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"""
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Sets the direction based on the previous direction we came from.
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"""
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# direction (index) of movement
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if p0.x!=p1.x:
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return 0
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elif p0.y!=p1.y:
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return 1
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else:
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# z direction
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return 2
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def contract_path(self,path):
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"""
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Remove intermediate points in a rectilinear path.
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"""
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newpath = [path[0]]
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for i in range(1,len(path)-1):
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prev_inertia=self.get_inertia(path[i-1],path[i])
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next_inertia=self.get_inertia(path[i],path[i+1])
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# if we switch directions, add the point, otherwise don't
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if prev_inertia!=next_inertia:
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newpath.append(path[i])
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# always add the last path
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newpath.append(path[-1])
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return newpath
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def add_path_blockages(self):
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"""
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Go through all of the past paths and add them as blockages.
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This is so we don't have to write/reload the GDS.
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"""
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for path in self.paths:
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for grid in path:
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self.rg.set_blocked(grid)
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