mirror of https://github.com/VLSIDA/OpenRAM.git
102 lines
4.2 KiB
Python
102 lines
4.2 KiB
Python
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# See LICENSE for licensing information.
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#
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# Copyright (c) 2016-2023 Regents of the University of California, Santa Cruz
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# All rights reserved.
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#
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from openram import debug
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from openram.base.vector import vector
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from .navigation_node import navigation_node
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from .navigation_blockage import navigation_blockage
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class navigation_graph:
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""" This is the navigation graph created from the blockages. """
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def __init__(self):
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pass
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def is_probe_blocked(self, p1, p2):
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"""
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Return if a probe sent from p1 to p2 encounters a blockage.
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The probe must be sent vertically or horizontally.
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This method assumes that blockages are rectangular.
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"""
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# Check if any blockage blocks this probe
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for blockage in self.nav_blockages:
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right_x = blockage.ur[0]
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upper_y = blockage.ur[1]
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left_x = blockage.ll[0]
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lower_y = blockage.ll[1]
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# Check if blocked vertically
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if is_between(left_x, right_x, p1.x) and (is_between(p1.y, p2.y, upper_y) or is_between(p1.y, p2.y, lower_y)):
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return True
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# Check if blocked horizontally
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if is_between(upper_y, lower_y, p1.y) and (is_between(p1.x, p2.x, left_x) or is_between(p1.x, p2.x, right_x)):
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return True
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return False
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def create_graph(self, layout_source, layout_target, layout_blockages):
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""" """
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debug.info(0, "Creating the navigation graph for source '{0}' and target'{1}'.".format(layout_source, layout_target))
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# Find the region to be routed and only include objects inside that region
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s_ll, sou_ur = layout_source.rect
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t_ll, tar_ur = layout_target.rect
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ll = vector(min(s_ll.x, t_ll.x), max(s_ll.y, t_ll.y))
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ur = vector(max(sou_ur.x, tar_ur.x), min(sou_ur.y, tar_ur.y))
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region = (ll, ur)
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# Instantiate "navigation blockage" objects from layout blockages
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self.nav_blockages = []
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for layout_blockage in layout_blockages:
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ll, ur = layout_blockage.rect
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if (is_between(region[0].x, region[1].x, ll.x) and is_between(region[0].y, region[1].y, ll.y)) or \
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(is_between(region[0].x, region[1].x, ur.x) and is_between(region[0].y, region[1].y, ur.y)):
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self.nav_blockages.append(navigation_blockage(ll, ur))
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self.nodes = []
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# Add source and target for this graph
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self.nodes.append(navigation_node(layout_source.center()))
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self.nodes.append(navigation_node(layout_target.center()))
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# Create the corner nodes
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for blockage in self.nav_blockages:
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self.nodes.extend(blockage.create_corner_nodes())
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# Create intersection nodes
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# NOTE: Intersection nodes are used to connect boundaries of blockages
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# perpendicularly.
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new_nodes = []
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debug.info(0, "Number of blockages: {}".format(len(self.nav_blockages)))
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debug.info(0, "Number of nodes: {}".format(len(self.nodes)))
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for i in range(len(self.nodes)):
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debug.info(3, "Creating intersections for node #{}".format(i))
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node1 = self.nodes[i]
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for j in range(i + 1, len(self.nodes)):
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node2 = self.nodes[j]
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# Skip if the nodes are already connected
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if node1 in node2.neighbors:
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continue
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# Try two different corners
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for k in [0, 1]:
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# Create a node at the perpendicular corner of these two nodes
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corner = navigation_node(vector(node1.position[k], node2.position[int(not k)]))
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# Skip this corner if the perpendicular connection is blocked
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if self.is_probe_blocked(corner.position, node1.position) or self.is_probe_blocked(corner.position, node2.position):
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continue
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corner.add_neighbor(node1)
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corner.add_neighbor(node2)
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new_nodes.append(corner)
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self.nodes.extend(new_nodes)
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debug.info(0, "Number of nodes after intersections: {}".format(len(self.nodes)))
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def is_between(a, b, mid):
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""" Return if 'mid' is between 'a' and 'b'. """
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return (a < mid and mid < b) or (b < mid and mid < a)
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