AT2004 Datasheet, PDF (17/25 Pages) List of Unclassifed Manufacturers – 4 Channels ADPCM Processor with Echo Cancellation and Conferencing

AT2004
4 Channels ADPCM Processor with Echo Cancellation and Conferencing
Sample Command Sequences:
ADPCM, conferencing, echo canceling, 32k, µ-Law, 8-half channels:
For convenience, each half duplex channel is assigned a number corresponding to the internal processing order of the channels. Channels
0 through Channel 3 correspond with ADPCM decode channels and Channels 4 through Channel 7 corresponds with ADPCM encode
channels.
The following is brief description of what each half duplex channel is running:
Channel 0: (decode ADPCM channel)
Conferencing:
Conferencing Disabled.
Gain Adjustment:
No output PCM gain adjustment (0 db gain).
Echo Canceling:
Channel 0 is a decode channel, thus output value is saved as a reference sample.
Delay (0)
MCU7byte Command:
• Decode (i.e. input is ADPCM sample sequence)
• u-Law output, 32k ADPCM algorithm.
• Input time slot: @yin[0:3] (beginning bit=0, ending bit=3)
• Output time slot: @yout[0:7] (beginning bit=0, ending bit=7)
Channel 1: (decode ADPCM channel)
Conferencing:
Conferencing Disabled.
Gain Adjustment:
No output PCM gain adjustment (0 db gain).
Echo Canceling:
Channel 1 is a decode channel, thus output value is saved as a reference sample.
Delay (0)
MCU7byte Command:
• Decode
• u-Law output, 32k ADPCM algorithm.
• Input time slot: @yin[16:19]
• Output time slot: @yout[16:23]
Channel 2: (decode ADPCM channel)
Conferencing:
Channel 0 + Channel 1 + Channel 4. (Note that conferencing always includes its own channel, in this
case ch 2).
Gain Adjustment:
No output PCM gain adjustment (0 db gain).
Echo Canceling:
Channel 2 is a decode channel, thus output value is saved as a reference sample.
Delay (0)
MCU7byte Command:
• Decode
• u-Law output, 32k ADPCM algorithm.
• Input time slot: @yin[32:35]
• Output time slot: @yout[32:39]
Channel 3: (decode ADPCM channel)
Conferencing:
Channel 4 + Channel 5 + Channel 6
Gain Adjustment:
No output PCM gain adjustment (0 db gain).
Echo Canceling:
Channel 3 is a decode channel, thus output value is saved as a reference sample.
Delay (0)
MCU7byte Command:
• Decode
• u-Law output, 32k ADPCM algorithm.
• Input time slot: @yin[48:51]
• Output time slot: @yout[48:55]
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©2001 Atelic System, Inc