AMBE-2000™ Vocoder Chip Users Manual
Version 4.92, June, 08
DVSI Confidential Proprietary, Subject to Change
Page 39
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5.4.2
Unframed Serial Input Format
The Unframed Input format contains 1 to 4 bits within each 16 bits serial output word. For the formats which contain more
than one bit each word the MSB of the data bits is considered first in the transmission. In Unframed mode, the header data
from Framed mode is dropped and each 16 bit write contains 1 to 4 coded voice data bits. The number of words that need to
be transferred into the decoder for each 20 millisecond frame will be the number of bits per frame divided by the number of
bits per word. So a system coding at 4800 bps with 3 bits per word will need to write exactly 32 ( [4800
÷
50]
÷
3 = 32)
words each frame.
Table 5-Q Unframed Serial Input Data Format
Data
Control Offset
Control Data
Bits per Word
See Table 4-A
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
1 bit per Word Format
D
msb
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
2 bits per Word Format
D
msb
D
0
0
0
0
0
0
0
0
0
0
0
0
0
0
3 bits per Word Format
D
msb
D
D
0
0
0
0
0
0
0
0
0
0
0
0
0
4 bits per Word Format
D
msb
D
D
D
0
0
0
0
0
0
0
0
0
0
0
0
