User's Manual

TC63 Hardware Interface Description
Strictly confidential / Draft
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TC63_HD_V00.432 Page 52 of 97 11.05.2005
3.13 Audio Interfaces
TC63 comprises three audio interfaces available on the board-to-board connector:
• Two analog audio interfaces, both with balanced or single-ended inputs/outputs.
• Serial digital audio interface (DAI) designed for PCM (Pulse Code Modulation).
This means you can connect up to three different audio devices, although only one interface
can be operated at a time. Using the AT^SAIC command you can easily switch back and
forth.
Analog switch
Digital
Audio
Interface
Ai
r
Interface
DSP
MUX
MU
X
D
A
MICN2
MICP2
MICN1
MICP1
USC6
USC5
USC4
USC3
USC2
AGND
USC0
USC1
D
A
EPP2
EPN2
EPP1
EPN1
VMIC
MUX
Figure 17: Audio block diagram
To suit different types of accessories the audio interfaces can be configured for different
audio modes via the AT^SNFS command. The electrical characteristics of the voiceband part
vary with the audio mode. For example, sending and receiving amplification, sidetone paths,
noise suppression etc. depend on the selected mode and can be altered with AT commands
(except for mode 1).
Both analog audio interfaces can be used to connect headsets with microphones or
speakerphones. Headsets can be operated in audio mode 3, speakerphones in audio
mode 2. Audio mode 5 can be used for a speech coder without signal pre or post processing.
When shipped from factory, all audio parameters of TC63 are set to interface 1 and audio
mode 1. This is the default configuration optimized for the Votronic HH-SI-30.3/V1.1/0
handset and used for type approving the Siemens reference configuration. Audio mode 1 has
fix parameters which cannot be modified. To adjust the settings of the Votronic handset
simply change to another audio mode.