User`s manual

AMBE-2000™ Vocoder Chip
User’s Manual Version 4.9
DVSI Confidential Proprietary, Subject to Change Page 23
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4.2 Serial Configuration Selection
The hardware interface to the Channel Interface is configured as a serial interface based exclusively on the hardware settings of
CHAN_SEL [1-0]. See Table 4-A.
Table 4-A Channel Interface Selection Table
Interface
Select Pins
Port Type
CHAN_SEL1
(pin 77)
CHAN_SEL0
(pin 75)
Active Framed 0 0
Active Unframed 0 1
Passive
Framed
1 0
Passive
Unframed
1 1
Table 4-B Unframed Bit per Word Selection Table
Interface
Select Pins
Number
of Voice
Data Bits
per Word
BAUD_SEL1
(pin 81)
BAUD_SEL0
(pin 80)
1 0 0
2 0 1
3 1 0
4 1 1
All transfers occur through a serial port. The serial port inputs and outputs a 16 bit word for every write and read strobe signal
respectively. Serial mode can be framed or unframed. Within the unframed mode, the data is input and output in 16 bits
words still but with only 1 to 4 voice data bits carried within each word. These four configurations can be seen in Table 4-B.
See section 4.3 for all the details on the serial interface.