M
ODEL
SL599 V
ERSION
V_1.0
P
REPARED BY
H/W
D
ATE
2007.04.11
S
UBJECT
T
ECHNICAL
M
ANUAL
P
AGE
28/52
SL599
T
ECHNICAL
M
ANUAL
7.
Audio Front-End
The audio front-end essentially comprises voice and audio data paths. The whole voice band data paths are
complied with GSM03.50 specification. Furthermore, Mono hands-free audio or external FM radio playback
path are provided. The stereo audio path facilitates audio quality playback, external FM radio, and voice
playback through headset.
Figure 24. Audio Front-End Block Diagram
Figure 25 shows the block diagram of digital circuits of the audio front-end. The APB register block is an APB
peripheral to get settings from the MCU. The DSP audio port block interfaces with the DSP for control and data
communications. Besides, there is a Digital Audio Interface(DAI) block to communicate with the System
Simulator for FTA or external Bluetooth module for particular applications. The digital filter block performs
filter operations for voice band and audio band signal processing.