
PSB 7280
Semiconductor Group
23
Data Sheet 1998-07-01
2.2.2
Audio Functions and Supplementary Features
General
The uncompressed/compressed audio is applied to the interfaces as follows:
“Transparent” means that data is received/transmitted in a time-slot without protocol.
1. Full Duplex G.728 Encoding/Decoding of One Audio Channel
Audio coding according to ITU-T G.728 fixed point recommendation using Low Delay
Code Excited Prediction (LD-CELP, 16 kbit/s), offering toll quality audio. The postfilter of
the G.728 may be switched on (offering a higher quality impression) or off (providing
objective better S/N values).
2. Full Duplex G.722 Encoding/Decoding of One Audio Channel
Audio coding for 7-kHz voice using the Sub-Band Coded Adaptive Differential PCM
(SB-ADPCM) algorithm according to the G.722 Recommendation.
3. Serial H.221/223 Oriented Audio Protocol
The PSB 7280 supports a serial H.221/223 oriented audio protocol for direct connection
to a Videocodec (VCP of 8
×
8 Inc.). This protocol provides an outband synchronization
of the audio bit streams by using block structures for the compressed audio data.
Uncompressed Audio
IOM-2 (transparent)
Compressed Audio
SAI (H.221/223 oriented audio protocol or
transparent)
Host IF (interrupt handshake protocol with
minimized interrupt load for the host)
Host IF (interrupt handshake protocol)
IOM-2 (transparent)
Host IF (interrupt handshake protocol)