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dbrochart |
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#### ####
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#### permut.py ####
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#### ####
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#### This file is part of the turbo decoder IP core project ####
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#### http://www.opencores.org/projects/turbocodes/ ####
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#### ####
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#### Author(s): ####
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#### - David Brochart(dbrochart@opencores.org) ####
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#### ####
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#### All additional information is available in the README.txt ####
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#### file. ####
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#### ####
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######################################################################
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#### ####
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#### Copyright (C) 2005 Authors ####
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#### ####
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#### This source file may be used and distributed without ####
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#### restriction provided that this copyright statement is not ####
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#### removed from the file and that any derivative work contains ####
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#### the original copyright notice and the associated disclaimer. ####
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#### ####
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#### This source file is free software; you can redistribute it ####
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#### and/or modify it under the terms of the GNU Lesser General ####
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#### Public License as published by the Free Software Foundation; ####
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#### either version 2.1 of the License, or (at your option) any ####
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#### later version. ####
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#### ####
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#### This source is distributed in the hope that it will be ####
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#### useful, but WITHOUT ANY WARRANTY; without even the implied ####
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#### warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR ####
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#### PURPOSE. See the GNU Lesser General Public License for more ####
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#### details. ####
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#### ####
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#### You should have received a copy of the GNU Lesser General ####
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#### Public License along with this source; if not, download it ####
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#### from http://www.opencores.org/lgpl.shtml ####
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#### ####
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######################################################################
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from myhdl import Signal, instance
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def zPermut(flipflop, z, zPerm, flip = 0):
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""" Extrinsic information permutation.
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flip -- initialisation (permutation on/off)
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flipflop -- in : permutation control signal (on/off)
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z -- in : original extrinsic information
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zPerm -- out : permuted extrinsic information
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"""
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@instance
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def zPermutLogic():
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while 1:
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if flipflop.val == bool(flip):
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zPerm[0].next = z[0].val
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zPerm[1].next = z[1].val
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zPerm[2].next = z[2].val
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zPerm[3].next = z[3].val
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else:
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zPerm[0].next = z[0].val
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zPerm[1].next = z[2].val
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zPerm[2].next = z[1].val
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zPerm[3].next = z[3].val
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yield flipflop, z[0], z[1], z[2], z[3]
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return zPermutLogic
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def abPermut(flipflop, a, b, abPerm, flip = 0):
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""" Systematic information permutation.
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flip -- initialisation (permutation on/off)
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flipflop -- in : permutation control signal (on/off)
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a, b -- in : original systematic information
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abPerm -- out : permuted systematic information
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"""
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@instance
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def abPermutLogic():
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while 1:
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if flipflop.val == bool(flip):
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abPerm[1].next = a.val
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abPerm[0].next = b.val
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else:
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abPerm[1].next = b.val
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abPerm[0].next = a.val
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yield flipflop, a, b
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return abPermutLogic
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