import gdsMill import tech from contact import contact import math import debug from globals import OPTS import grid from pin_layout import pin_layout from vector import vector from vector3d import vector3d from router import router from direction import direction class supply_router(router): """ A router class to read an obstruction map from a gds and routes a grid to connect the supply on the two layers. """ def __init__(self, gds_name=None, module=None): """ 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, module) # Power rail width in grid units. self.rail_track_width = 2 def create_routing_grid(self): """ Create a sprase routing grid with A* expansion functions. """ size = self.ur - self.ll debug.info(1,"Size: {0} x {1}".format(size.x,size.y)) import supply_grid self.rg = supply_grid.supply_grid(self.ll, self.ur, self.track_width) def route(self, cell, layers, vdd_name="vdd", gnd_name="gnd"): """ Add power supply rails and connect all pins to these rails. """ debug.info(1,"Running supply router on {0} and {1}...".format(vdd_name, gnd_name)) self.cell = cell self.vdd_name = vdd_name self.gnd_name = gnd_name # 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.find_pins(vdd_name) self.find_pins(gnd_name) self.add_blockages() self.add_pin_blockages(vdd_name) self.route_supply_rails(gnd_name,0) self.connect_supply_rail(gnd_name) self.route_pins_to_rails(gnd_name) # Start fresh. Not the best for run-time, but simpler. self.clear_blockages() self.add_blockages() self.add_pin_blockages(gnd_name) self.route_supply_rails(vdd_name,1) self.connect_supply_rail(vdd_name) self.route_pins_to_rails(vdd_name) self.write_debug_gds() return False def connect_supply_rail(self, name): """ Add vias between overlapping supply rails. """ paths = [x for x in self.paths if x.name == name] # Split into horizontal and vertical vertical_paths = [x for x in paths if x[0][0].z==1] horizontal_paths = [x for x in paths if x[0][0].z==0] shared_areas = [] for v in vertical_paths: for h in horizontal_paths: overlap = v.overlap(h) if overlap: shared_areas.append(overlap) for (ll,ur) in shared_areas: center = (ll + ur).scale(0.5,0.5,0) self.add_via(center,self.rail_track_width) def route_supply_rails(self, name, supply_number): """ Route the horizontal and vertical supply rails across the entire design. """ start_offset = supply_number*self.rail_track_width max_yoffset = self.rg.ur.y max_xoffset = self.rg.ur.x step_offset = 2*self.rail_track_width # Horizontal supply rails for offset in range(start_offset, max_yoffset, step_offset): # Seed the function at the location with the given width wave = [vector3d(0,offset+i,0) for i in range(self.rail_track_width)] # While we can keep expanding east in this horizontal track while wave and wave[0].x < max_xoffset: wave = self.route_supply_rail(name, wave, direction.EAST) # Vertical supply rails max_offset = self.rg.ur.x for offset in range(start_offset, max_xoffset, step_offset): # Seed the function at the location with the given width wave = [vector3d(offset+i,0,1) for i in range(self.rail_track_width)] # While we can keep expanding north in this vertical track while wave and wave[0].y < max_yoffset: wave = self.route_supply_rail(name, wave, direction.NORTH) # Remember index of path size which is how many rails we had at the start self.num_rails = len(self.paths) def route_supply_rail(self, name, seed_wave, direct): """ This finds the first valid starting location and routes a supply rail in the given direction. It returns the space after the end of the rail to seed another call for multiple supply rails in the same "track" when there is a blockage. """ # Sweep to find an initial unblocked valid wave start_wave = self.rg.find_start_wave(seed_wave, len(seed_wave), direct) if not start_wave: return None # Expand the wave to the right wave_path = self.rg.probe(start_wave, direct) if not wave_path: return None # Filter any path that won't span 2 rails # so that we can guarantee it is connected if len(wave_path)>=2*self.rail_track_width: self.add_wavepath(name, wave_path) wave_path.name = name self.paths.append(wave_path) # seed the next start wave location wave_end = wave_path[-1] return wave_path.neighbor(direct) def route_pins_to_rails(self,pin_name): """ This will route each of the pin components to the supply rails. After it is done, the cells are added to the pin blockage list. """ # For every component for index in range(self.num_pin_components(pin_name)): # Block all the pin components first self.add_component_blockages(pin_name) # Add the single component of the pin as the source # which unmarks it as a blockage too self.add_pin_component(pin_name,index,is_source=True) # Add all of the rails as targets # Don't add the other pins, but we could? self.add_supply_rail_target(pin_name) # Actually run the A* router self.run_router(detour_scale=5)