PSB7238 SIEMENS [Siemens Semiconductor Group], PSB7238 Datasheet - Page 22

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

Semiconductor Group
Two receive and two transmit audio channels are provided. They are input/output on the
ISDN Oriented Modular (IOM-2) or the Serial Audio Interface (SAI) interfaces in
individually programmable time-slots. These channels are accessed from the DSP
and/or the parallel host interface.
The two HDLC Controller channels can be serviced by the DSP or the parallel host
interface. The serial data for the HDLC controllers are located in programmable
time-slots on IOM-2 and/or SAI.
For development purposes, the External Memory Interface allows programs to be
executed from an external memory and external data memory to be used.
2.2
2.2.1
The main functions implemented by the PSB 7238 are:
– G.728 compression/decompression (16 Kbit/s)
– G.723 compression/decompression (6.3, 5.3 Kbit/s)
– G.722 compression/decompression for 7-kHz audio (64, 56, 48 Kbit/s)
– G.711 compression/decompression (64 Kbit/s)
– Digital sampling rate conversion (16 kHz - 8 kHz) for G.722 audio with 8-kHz codec
– Accepts/outputs uncompressed audio 8-bit PCM A/ law or 16-bit linear format
– Uncompressed/compressed
– Inband controlled H.221/H.223 oriented audio protocol, e.g. for direct serial
– Outband controlled audio protocol with optimized data rate
– Stable reaction on interrupt handshake timing violations of e.g. a slow host
For more details on the hardware (necessary for a better understanding of some of the
topics described in the present chapter), please refer to the other chapters of this data
sheet.
(bandwidth reduced to 3.4 kHz)
combinations (IOM/Serial Audio Interface, IOM/Host, Host/Host)
connection to videocodec (VCP of 8 8 Inc., formerly IIT Inc.)
(Windows
Functions
Summary of the Functions
®
PC)
audio
switchable
22
General Architecture and Functions
between
Data Sheet 1998-07-01
different
PSB 7238
interface