User`s manual

AMBE-3000™-HDK Development Board
User’s Manual Version 1.1
Page 37
DVSI Confidential Proprietary
Operation
LoopBack Mode
LoopBack Mode using the AMBE-3000™ Vocoder chip’s Parallel Interface.
In Loopback the AMBE-3000™ Vocoder chip (Parallel Interface), analog speech from the handset or
RCA jack input connections gets digitized by the codec, encoded by the AMBE-3000™ Vocoder chip
and sent out its parallel interface to the micro controller. The encoded data is then returned back to the
AMBE-3000™ vocoder chip, where it gets decoded, sent to the codec, and output the RCA jacks or
handset depending on the user settings.
Figure 21 LoopBack PPT Mode AMBE-3000™ Vocoder Chip (Parallel Interface)
LoopBack Mode using the AMBE-3000™ Vocoder chip’s UART Interface
In Loopback the AMBE-3000™ Vocoder chip UART Interface Analog speech input from the handset or
RCA jack input connections gets digitized by the codec then encoded the AMBE-3000™ Vocoder chip.
The encoded data is then sent out the chips UART interface to the P2 connector. This data is then
loopbacked to the micro controller by physically connecting a null modem serial cable to the DB9
connectors P2 and P1. The microcontroller then sends the data to the AMBE-3000™ vocoder chip,
where it gets decoded and sent to the codec to be output the RCA jacks or handset depending on the
user settings.