decoders/ac97/__init__.py

   1 ##
   2 ## This file is part of the libsigrokdecode project.
   3 ##
   4 ## Copyright (C) 2017 Gerhard Sittig <gerhard.sittig@gmx.net>
   5 ##
   6 ## This program is free software; you can redistribute it and/or modify
   7 ## it under the terms of the GNU General Public License as published by
   8 ## the Free Software Foundation; either version 2 of the License, or
   9 ## (at your option) any later version.
  10 ##
  11 ## This program is distributed in the hope that it will be useful,
  12 ## but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 ## GNU General Public License for more details.
  15 ##
  16 ## You should have received a copy of the GNU General Public License
  17 ## along with this program; if not, see <http://www.gnu.org/licenses/>.
  18 ##
  19
  20 '''
  21 AC'97 (Audio Codec '97) is a protocol for audio and modem I/O functionality
  22 in mainstream PC systems.
  23
  24 AC'97 communicates full duplex data (SDATA_IN, SDATA_OUT), where bits
  25 are clocked by the BIT_CLK and frames are signalled by the SYNC signals.
  26 A low active RESET# line completes the set of signals.
  27
  28 Frames repeat at a nominal frequency of 48kHz, and consist of 256 bits
  29 each. One 16bit slot contains management information, twelve 20bit slots
  30 follow which carry data for three management and nine audio/modem channels.
  31 Optionally two slots of one frame can get combined for higher resolution
  32 on fewer channels, or double data rate.
  33
  34 Details:
  35 http://download.intel.com/support/motherboards/desktop/sb/ac97_r23.pdf
  36 '''
  37
  38 from .pd import Decoder