
PSB 7238
Firmware Features
Semiconductor Group
131
Data Sheet 1998-07-01
6.2
Audio Interfaces
In order to cover a wide range of applications, the JADE offers a variety of different
interface combinations and protocols for the uncompressed/compressed data
exchange.
The basic interfacing is like in
Figure 41
:
Figure 41
Two interfaces are necessary, one for compressed audio connected to a User and one
for uncompressed audio connected to a Codec.
By switching the compressed/uncompressed data stream to different hardware
interfaces (Host, IOM, Serial Audio Interface), the JADE is able to support standalone
solutions using a video processor (compressed data provided on Serial Audio Interface)
as well as host systems (e.g. software video coders using the host interface for the
compressed data) or offline audio compression (compressed and uncompressed audio
exchanged through host interface).
The audio interface description is split up into two basic parts: In the first part the protocol
(data format, data packet size) and mode control (inband or outband) are described
(
Section 6.2.1
and
Section 6.2.2
) which are independent of the selected
hardware-interface combination, in the second part the individual timings and
handshake procedures for the selected hardware-interface combination are described
(
Section 6.2.3
).
6.2.1
In the following sections the protocols for the exchange of compressed audio data
between the JADE and a user are described.
Compressed Audio Protocols and Control of JADE
6.2.1.1
All times that are given in this chapter refer to realtime processing of a 10 ms frame
length of the audio data, which is the default setting of the JADE. When doing offline
processing (compressed and uncompressed data exchanged through the host), the
delay times in this chapter have to be substituted by the corresponding number of
Outband Control of JADE