AMBE2000 Datasheet, PDF (29/47 Pages) List of Unclassifed Manufacturers – VOCODER CHIP

AMBE-2000™ Vocoder Chip
User’s Manual Version 3.0
Echo Canceller (EC) :
Set this bit to 1 to enable the echo cancel function on a frame by frame basis. This must be set to 1 in every packet sent to
continue use.
Sleep (SL) :
Set this bit to 1 to enter Sleep mode on a frame by frame basis. Sleep is a low power mode, not to be confused with Power
Down Mode. The sleep function must be enabled in every packet to continue in sleep mode. Set this bit to 0 to exit Sleep
mode.
VAD :
In order to set the Voice Activity Detector on, set the VAD bit to 1. To disable Voice Activity Detection, set the VAD bit to 0.
5.2.10 Formatted Input : Words 12-23 : Channel Data
This is the field that contains the actual coded bits. Input of the data begins with the MSB of the first word in this field and
continues through with the final bit output being the LSB of the final word. If the data rate selected is less than 9600bps then
the unused bits in each frame are zero and populate the end of the field. As is noted in the Channel Interface definitions, these
unused bits must still be clocked out of the AMBE-2000™. The packet must always consist of 24 words.
5.3 Formatted Output Format
The format for Formatted output data is shown in Figure 5-B. It is only the bits in the Voice Data Bits field, which are
transmitted along with framing information (data used to locate the start of each frame for proper reconstruction at the decoder)
over the channel. The first 192 bits provide overhead information, which is sometimes useful to the host but is generally not
transmitted over the channel.
Figure 5-B Basic Formatted Output Format
Word #
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
Description
Header always set to 0x13ec
Power Control (8bits)
Control Word 1 (8 bits) – see Table 5-J
Rate info 0
Rate info 1
Rate info 2
Rate info 3
Rate info 4
Bit Error Rate
Unused
Unused
DTMF Control – see Table 5-L
Control Word 2 – see Table 5-N
Channel Data
Channel Data
Channel Data
Channel Data
Channel Data
Channel Data
Channel Data
Channel Data
Channel Data
Channel Data
Channel Data
Channel Data
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