
PSB 7238
Firmware Features
Semiconductor Group
140
Data Sheet 1998-07-01
P(1-0)
Part number of the data in this packet. Allows the natural period of the data
to be 10 to 40 ms. For G.723 takes on the values 0, 1 or 2 corresponding to
the first, second or third part of a 30 ms data packet. Is always 0 for the other
modes.
Note: To avoid the updating of these bits by the user in each frame when
operating in G.723 mode, the JADE auto-increments the P-bits.
Nevertheless, the user has to take care that G.723 encoder and
decoder are running synchronously, i.e. the part number of the
received and transmitted packet in one 10 ms frame must be identical
for control and status. For that, after switching to G.723 mode the user
has to read the P(1-0) status bits and synchronize the data stream
transmitted to the JADE correspondingly, i.e. if the user reads a status
value of 2 it has to transmit part 0 of the next 30 ms data packet in the
next 10 ms frame.
The P(1-0) control block bits sent by a user are ignored by the JADE when
operating in G.723 mode. This is to avoid collisions between the host and the
auto-increment mechanism in the JADE.
00
First part of compressed audio packet (G.723: part 1/3)
01
Second part of compressed audio packet (G.723: part 2/3)
10
Third part of compressed audio packet (G.723: part 3/3)
11
Fourth part of compressed audio packet (G.723: reserved)
Loopback modes, used for testing the audio subsystem.
000
No loopback (default)
001
Send received compressed data back to the user as encode data
010
Encode the decoded user data
011
Reserved
100
Reserved
101
Decode the encoded audio input data
110
Send the digital ADC output to the DAC input
111
Reserved
L(2-0)