
PSB 7280
Semiconductor Group
151
Data Sheet 1998-07-01
The size of the command and data packets is the following (header excluded):
The communication between user and JADE starts in the neutral mode. To initiate
transfer of speech data, the user sends a command data structure set to the desired
compression mode(s) in a neutral size packet. The mode change affects the JADE’s
input pipeline stage in the next 10 ms period. This means that if the decode mode
changes, the next packet from the user will change in size (corresponding to the new
decode mode), while if the encode mode changes, the third packet from the JADE will
be affected (packets from the JADE represent the output stage of the pipeline). As a
general rule, any changes to the current operating mode or opetions (volume, mute, etc.)
transferred to the JADE from the user take effect on the input captured on the next 10
ms boundary.
To change compression modes, the user must first send two neutral mode command
packets. The first neutral mode command will be in a full-size packet per the current
operating mode, while the following neutral mode command packet does only contain
the 8 words header. Two neutral packets are required to clear the JADE’s pipeline.
During that time the JADE will reorganize its memory (if required) and re-initialize internal
variables.
Note: When a mode change is requested by the user without sending two neutral
packets before, the JADE may not work stable.
Mode
Neutral
G.728
G.711
G.722
8-kHz pass-through
16-kHz pass-through
Compressed Words
0
40
40
40
80
160