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Fix VCG error in channel route. 

Note, the channel routing algorithm still does not handle
horizontal conflicts or cyclic vertical conflicts!
This commit is contained in:
Matt Guthaus 2018-08-15 14:19:04 -07:00
parent 6e332e581a
commit e3f2ee8a7e
1 changed files with 18 additions and 13 deletions
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31
compiler/base/hierarchy_layout.py
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@ -718,7 +718,7 @@ class layout(lef.lef):
conflicts between pins.
"""
def remove_pin_from_graph(pin, g):
def remove_net_from_graph(pin, g):
# Remove the pin from the keys
g.pop(pin,None)
# Remove the pin from all conflicts
@ -726,7 +726,8 @@ class layout(lef.lef):
for other_pin,conflicts in g.items():
if pin in conflicts:
conflicts.remove(pin)
vcg[other_pin]=conflicts
g[other_pin]=conflicts
return g
if not pitch:
pitch = self.m2_pitch
@ -740,20 +741,24 @@ class layout(lef.lef):
# Initialize the vertical conflict graph (vcg) and make a list of all pins
vcg = {}
for (top_name, bot_name) in route_map:
vcg[top_name] = []
vcg[bot_name] = []
# Find the vertical pin conflicts
# FIXME: O(n^2) but who cares for now
for top_name,top_pin in top_pins.items():
vcg[top_name]=[]
for bot_name,bot_pin in bottom_pins.items():
if not vertical and abs(top_pin.center().x-bot_pin.center().x) < pitch:
vcg[top_name].append(bot_name)
vcg[bot_name].append(top_name)
elif vertical and abs(top_pin.center().y-bot_pin.center().y) < pitch:
vcg[top_name].append(bot_name)
vcg[bot_name].append(top_name)
# Remember, vertical is the boolean of the routes in the channel
# so check the intervals of the pins in the other dimension
x_overlap = abs(top_pin.center().x-bot_pin.center().x)<pitch
y_overlap = abs(top_pin.center().y-bot_pin.center().y)<pitch
if (vertical and y_overlap) or (not vertical and x_overlap):
try:
vcg[bot_name].append(top_name)
except:
vcg[bot_name] = [top_name]
#FIXME: What if we have a cycle?
# This is the starting offset of the first trunk
if vertical:
@ -770,7 +775,7 @@ class layout(lef.lef):
route_pin=None
for route_pin,conflicts in vcg.items():
if len(conflicts)==0:
remove_pin_from_graph(route_pin,vcg)
vcg=remove_net_from_graph(route_pin,vcg)
break
# Get the connected pins from the routing map
@ -781,7 +786,7 @@ class layout(lef.lef):
# Remove the other pins from the conflict graph too
for other_pin in pin_connections:
remove_pin_from_graph(other_pin, vcg)
vcg=remove_net_from_graph(other_pin, vcg)
# Create a list of the pins rather than a list of the names
pin_list = [all_pins[pin_name] for pin_name in pin_connections]