mirror of https://github.com/VLSIDA/OpenRAM.git
51 lines
1.5 KiB
Python
51 lines
1.5 KiB
Python
# See LICENSE for licensing information.
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#
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# Copyright (c) 2016-2022 Regents of the University of California and The Board
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# of Regents for the Oklahoma Agricultural and Mechanical College
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# (acting for and on behalf of Oklahoma State University)
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# All rights reserved.
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#
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from openram import debug
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class drc_lut():
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"""
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Implement a lookup table of rules.
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Each element is a tuple with the last value being the rule.
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It searches through backwards until all of the key values are
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met and returns the rule value.
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For exampe, the key values can be width and length,
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and it would return the rule for a wire of at least a given width and length.
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A dimension can be ignored by passing inf.
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"""
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def __init__(self, table):
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self.table = table
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def __call__(self, *key):
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"""
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Lookup a given tuple in the table.
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"""
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if len(key)==0:
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first_key = list(sorted(self.table.keys()))[0]
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return self.table[first_key]
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for table_key in sorted(self.table.keys(), reverse=True):
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if self.match(key, table_key):
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return self.table[table_key]
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def match(self, key1, key2):
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"""
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Determine if key1>=key2 for all tuple pairs.
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(i.e. return false if key1<key2 for any pair.)
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"""
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# If any one pair is less than, return False
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debug.check(len(key1) == len(key2), "Comparing invalid key lengths.")
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for k1, k2 in zip(key1, key2):
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if k1 < k2:
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return False
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return True
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