Operating Modes; Basic Mode; Advanced Mode; Voiceband Mode Pcm Bus Coding Format - Motorola 8900 - Blackberry Curve Cell Phone OEM Car Charger Developer's Manual

Audio Interface
Figure 2-21
Figure 2-21: Voiceband Mode PCM Bus Coding Format

Operating Modes

The C24 audio interface includes 2 modes of operation. Each operating mode defines the audio
input and output devices to be used for each audio sound type and their programmable settings.

Basic Mode

Basic mode is the C24 default power-up audio configuration. Several audio paths are available in
this mode, and their settings can be programmed through the AT command set.
Table 2-10
Audio Path
Handset
Headset
Alert
Digital

Advanced Mode

Advanced mode utilizes C24's unique set of AT commands for advanced audio programming.
The expanded AT command set enables to define a specific audio path and setting, which are not
part of the default configuration, for each type of audio sound (speech, DTMF tones, rings and
alerts).
32
illustrates the PCM bus format of the voiceband audio configuration.
describes the available audio paths in Basic mode.
Table 2-10: Basic Mode Audio Paths
Input Signal
MIC
HDST_MIC
PCM_DIN
C24 Module Hardware Description
Output Signal
SPKR_N, SPKR_P Default audio path for speech and
DTMF tones.
SPKR_N, SPKR_P Alternate path for headset device.
Enable by setting HDST_INT_N
interface signal low.
ALRT_N, ALRT_P Default alert and ringer loudspeaker
output port.
PCM_DOUT Enable digital path by
AT+MADIGITAL=1
Description
December 15, 2008