ac97: introduce first AC'97 decoder implementation (bits, slots, binary)

[libsigrokdecode.git] / decoders / ac97 / __init__.py

diff --git a/decoders/ac97/__init__.py b/decoders/ac97/__init__.py
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+##
+## This file is part of the libsigrokdecode project.
+##
+## Copyright (C) 2017 Gerhard Sittig <gerhard.sittig@gmx.net>
+##
+## This program is free software; you can redistribute it and/or modify
+## it under the terms of the GNU General Public License as published by
+## the Free Software Foundation; either version 2 of the License, or
+## (at your option) any later version.
+##
+## This program 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 General Public License for more details.
+##
+## You should have received a copy of the GNU General Public License
+## along with this program; if not, see <http://www.gnu.org/licenses/>.
+##
+
+'''
+AC'97 (Audio Codec '97) was specifically designed by Intel for audio and
+modem I/O functionality in mainstream PC systems. See the specification in
+http://download.intel.com/support/motherboards/desktop/sb/ac97_r23.pdf
+
+AC'97 communicates full duplex data (SDATA_IN, SDATA_OUT), where bits
+are clocked by the BIT_CLK and frames are signalled by the SYNC signals.
+A low active RESET# line completes the set of signals.
+
+Frames repeat at a nominal frequency of 48kHz, and consist of 256 bits
+each. One 16bit slot contains management information, twelve 20bit slots
+follow which carry data for three management and nine audio/modem channels.
+Optionally two slots of one frame can get combined for higher resolution
+on fewer channels, or double data rate.
+'''
+
+from .pd import Decoder