PSB7238 SIEMENS [Siemens Semiconductor Group], PSB7238 Datasheet - Page 141

• Manufacturer Part Number: PSB7238
• Description: Joint Audio Decoder-Encoder - Multimode
• Manufacturer: SIEMENS [Siemens Semiconductor Group]

OPT2
Value after reset: 00
S
Re(1-0),
Rd(1-0)
Semiconductor Group
(MSB)
0
Sampling Rate of the codec connected to the JADE, either 8 kHz or
16 kHz. If the sampling rate of the codec is different from the sampling
rate expected by the selected speech coder, the JADE automatically
uses over-/undersampling filters to convert the audio data.
When using G.728 mode and S = 1 indicating a 16-kHz codec is
connected, the postfilter of G.728 is switched off to ensure the
computational power for the over-/undersampling filters is available.
The effect on the audio quality is negligible.
When using G.722 mode and S = 0 indicating an 8-kHz codec is
connected, the bandwidth of the G.722 input/output data is reduced to
3.4 kHz. Nevertheless, the compressed data stream is fully compatible
and interoperable with the G.722 standard.
0
1
Restricted number of bits for encode and decode. Only used for G.722,
that offers modes where less than 8 bits per byte are used: 7 bits per
byte (56 Kbit/s) and 6 bits per byte (48 Kbit/s).
00
01
10
11
G.723 uses these bits in a different way. When the encode mode is
G.723 the Re bits give the desired encoding method:
00
01
10
11
Rd is the same as the above, but indicates the mode of the data in this
packet. It is the same as the corresponding bits of the G.723 packet
data.
H
S
Codec has 8 kHz sampling rate
Codec has 16 kHz sampling rate
8 valid bits per byte
7 valid bits per byte
6 valid bits per byte
Reserved
High rate, don’t use silence suppression
High rate, use silence suppression
Low rate, don’t use silence suppresion
Low rate, use silence suppression
Re1
Re0
141
Rd1
Rd0
Mailbox Address 06
e
Data Sheet 1998-07-01
Firmware Features
(LSB)
d
PSB 7238
H