📄 punct.py
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########################################################################## ######## punct.py ######## ######## This file is part of the turbo decoder IP core project ######## http://www.opencores.org/projects/turbocodes/ ######## ######## Author(s): ######## - David Brochart(dbrochart@opencores.org) ######## ######## All additional information is available in the README.txt ######## file. ######## ############################################################################## ######## Copyright (C) 2005 Authors ######## ######## This source file may be used and distributed without ######## restriction provided that this copyright statement is not ######## removed from the file and that any derivative work contains ######## the original copyright notice and the associated disclaimer. ######## ######## This source file is free software; you can redistribute it ######## and/or modify it under the terms of the GNU Lesser General ######## Public License as published by the Free Software Foundation; ######## either version 2.1 of the License, or (at your option) any ######## later version. ######## ######## This source is distributed in the hope that it will be ######## useful, but WITHOUT ANY WARRANTY; without even the implied ######## warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR ######## PURPOSE. See the GNU Lesser General Public License for more ######## details. ######## ######## You should have received a copy of the GNU Lesser General ######## Public License along with this source; if not, download it ######## from http://www.opencores.org/lgpl.shtml ######## ##########################################################################from myhdl import Signal, intbv, always_comb, instances, posedge, negedgedef punct(clk, rst, y1, y2, y1Int, y2Int, y1Punct, y2Punct, y1IntPunct, y2IntPunct, rate = 13): """ Puncturing mechanism. rate -- code rate (e.g. 13 for rate 1/3) clk, rst -- in : clock and negative reset y1, y2, y1Int, y2Int -- in : original data y1Punct, y2Punct, y1IntPunct, y2IntPunct -- out : punctured data """ y1Sel = Signal(bool(0)) y2Sel = Signal(bool(0)) punctSel_i0 = punctSel(clk, rst, y1Sel, y2Sel, rate) punctMux_i0 = punctMux(y1Sel, y2Sel, y1, y2, y1Int, y2Int, y1Punct, y2Punct, y1IntPunct, y2IntPunct) return instances()def punctSel(clk, rst, y1Sel, y2Sel, rate = 13): """ Puncturing selection (between original data (1) and 0 (0)). clk, rst -- in : clock and negative reset y1Sel, y2Sel -- out : selection signals (1 -> original data, 0 -> 0) """ if rate == 13: pattern = [[1], [1]] elif rate == 25: pattern = [[1, 1], [1, 0]] elif rate == 12: pattern = [[1], [0]] elif rate == 23: pattern = [[1, 0], [0, 0]] elif rate == 34: pattern = [[1, 0, 0], [0, 0, 0]] elif rate == 45: pattern = [[1, 0, 0, 0], [0, 0, 0, 0]] elif rate == 67: pattern = [[1, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0]] else: print "ERROR: the code rate you specified is not valid!" cntMax = len(pattern[0]) cnt = Signal(intbv(0, 0, cntMax)) while 1: if rst.val == 0: y1Sel.next = 0 y2Sel.next = 0 cnt.next = 0 else: if cnt.val < cntMax - 1: cnt.next = cnt.val + 1 else: cnt.next = 0 y1Sel.next = pattern[0][int(cnt.val)] y2Sel.next = pattern[1][int(cnt.val)] yield posedge(clk), negedge(rst)def punctMux(y1Sel, y2Sel, y1, y2, y1Int, y2Int, y1Punct, y2Punct, y1IntPunct, y2IntPunct): """ Puncturing mux. y1Sel, y2Sel -- in : selection signals (1 -> original data, 0 -> 0) y1, y2, y1Int, y2Int -- in : original data y1Punct, y2Punct, y1IntPunct, y2IntPunct -- out : punctured data """ def punctMuxLogic(): if y1Sel.val == 1: y1Punct.next = y1.val y1IntPunct.next = y1Int.val else: y1Punct.next = 0 y1IntPunct.next = 0 if y2Sel.val == 1: y2Punct.next = y2.val y2IntPunct.next = y2Int.val else: y2Punct.next = 0 y2IntPunct.next = 0 return always_comb(punctMuxLogic)⌨️ 快捷键说明
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