AT2004 Datasheet, PDF (9/25 Pages) List of Unclassifed Manufacturers – 4 Channels ADPCM Processor with Echo Cancellation and Conferencing

AT2004
4 Channels ADPCM Processor with Echo Cancellation and Conferencing
Command Byte [7:0]
Description
00
0
0
0 0 A1 A0 Chip Setup Command Header with A1, A0 chip ID
In/Out Conf_ind ADPCM_ind EC ref. chan. # Channel In/Out source, Conferencing/ADPCM indicator and EC’s
reference Channel #.
0 Dec
0
1
1 1 Rate ADPCM, configuration command for Channel #0
Delay (ms)
Specify delay for EC, should be multiple of 2ms
Input Begin Bit
Input End Bit
These commands specify the begin and ending bits of input data and
output data for channel #0
Output Begin Bit
Output End Bit
In/Out Conf_ind ADPCM_ind 0 0 0 0 Channel In/Out source, Conferencing/ADPCM indicator and EC’s
reference Channel #.
0 Dec
0
1
1 1 Rate ADPCM, configuration command for Channel #1
Delay (ms)
Specify delay for EC, should be multiple of 2ms
Input Begin Bit
Input End Bit
These commands specify the begin and ending bits of input data and
output data for channel #1
Output Begin Bit
Output End Bit
11
1
1
1 1 1 1 Footer of Chip Setup.
Note: The format of data fields In/Out, Conf_ind, ADPCM_ind, EC ref. Chan. #, Dec, Rate and Delay are specified below.
In/Out Description
0 0 Input on Xin, Output on Xout
0 1 Input on Xin, Output on Yout
1 0 Input on Yin, Output on Xout
1 1 Input on Yin, Output on Yout
Default: Input is on Xin, Output is on Xout for ADPCM encoding functions.
Input is on Yin, Output is on Yout for ADPCM decoding functions.
Conf_ind Description
0
No resource is allocated
for conferencing operation
1
Allocate resource for
conferencing operation
Default: 0, no resource is allocated for conferencing
ADPCM_ind Description
0
No resource is allocated
for ADPCM operation
1
Allocate resource for
ADPCM operation
Default: 1, allocate resource for ADPCM operation
“EC ref. Chan. #” specifies the channel number from which the echo canceller derives its reference signal.
Dec Description
0 ADPCM (Input is PCM, Output is ADPCM) encode
channel
1 ADPCM (Input is ADPCM, Output is PCM) decode
channel
Page 9 of 25
©2001 Atelic System, Inc