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Use safe regions to protect pin nodes

This commit is contained in:
Eren Dogan 2023-07-29 08:17:00 -07:00
parent 091d0f8775
commit 4c73d3aa7c
1 changed files with 51 additions and 20 deletions
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71
compiler/router/graph.py
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@ -43,6 +43,30 @@ class graph:
return shape.on_segment(ll, point, ur)
def get_safe_pin_values(self, pin):
""" Get the safe x and y values of the given pin. """
pin = pin.get_core()
offset = self.router.offset
spacing = self.router.track_space
size_limit = snap(offset * 4 + spacing)
x_values = []
y_values = []
if pin.width() > size_limit:
x_values.append(snap(pin.lx() + offset))
x_values.append(snap(pin.rx() - offset))
else:
x_values.append(snap(pin.cx()))
if pin.height() > size_limit:
y_values.append(snap(pin.by() + offset))
y_values.append(snap(pin.uy() - offset))
else:
y_values.append(snap(pin.cy()))
return x_values, y_values
def is_probe_blocked(self, p1, p2):
"""
Return if a probe sent from p1 to p2 encounters a blockage.
@ -68,6 +92,17 @@ class graph:
def is_node_blocked(self, node, pin_safe=True):
""" Return if a node is blocked by a blockage. """
def closest(value, checklist):
""" Return the distance of the closest value in the checklist. """
min_diff = float("inf")
for other in checklist:
diff = snap(abs(value - other))
if diff < min_diff:
min_diff = diff
return min_diff
offset = self.router.offset
spacing = self.router.track_space + offset + drc["grid"]
blocked = False
for blockage in self.graph_blockages:
# Check if two shapes overlap
@ -77,7 +112,6 @@ class graph:
continue
blockage = blockage.get_core()
if self.inside_shape(node.center, blockage):
offset = self.router.offset
p = node.center
lengths = [blockage.width(), blockage.height()]
centers = blockage.center()
@ -92,8 +126,15 @@ class graph:
safe[i] = False
if not all(safe):
blocked = True
elif pin_safe and blockage in [self.source, self.target]:
return False
continue
xs, ys = self.get_safe_pin_values(blockage)
xdiff = closest(p.x, xs)
ydiff = closest(p.y, ys)
if xdiff == 0 and ydiff == 0:
if pin_safe and blockage in [self.source, self.target]:
return False
elif xdiff < spacing and ydiff < spacing:
blocked = False
else:
blocked = True
return blocked
@ -204,25 +245,15 @@ class graph:
y_values = set()
# Add inner values for blockages of the routed type
x_offset = vector(self.router.offset, 0)
y_offset = vector(0, self.router.offset)
offset = self.router.offset
spacing = self.router.track_space
size_limit = snap(offset * 4 + spacing)
for shape in self.graph_blockages:
if not self.is_routable(shape):
continue
shape = shape.get_core()
aspect_ratio = shape.width() / shape.height()
# FIXME: Aspect ratio may not be the best way to determine this
# If the pin is tall or fat, add two points on the ends
if aspect_ratio <= 0.5: # Tall pin
points = [shape.bc() + y_offset, shape.uc() - y_offset]
elif aspect_ratio >= 2: # Fat pin
points = [shape.lc() + x_offset, shape.rc() - x_offset]
else: # Square-like pin
points = [shape.center()]
for p in points:
p = snap(p)
x_values.add(p.x)
y_values.add(p.y)
xs, ys = self.get_safe_pin_values(shape)
x_values.update(xs)
y_values.update(ys)
# Add corners for blockages
offset = vector(drc["grid"], drc["grid"])
@ -236,7 +267,7 @@ class graph:
# Add center values for existing vias
for via in self.graph_vias:
point = via.center()
p = via.center()
x_values.add(p.x)
y_values.add(p.y)