Figure 65 Audio interface
The digital uplink microphones are connected directly to RAPU. There are two uplink microphones: primary
and secondary. They are required for the uplink Two Microphone Noise Cancellation (2micNC) algorithm and
are located at the lower end of the phone.
Stereo output is provided by a separate stereo audio amplifier which is connected to EM ASIC. The output
from the stereo audio amplifier is fed to the AV connector.
The earpiece is driven by Tulppa chip which includes an amplifier and Earpiece Active Noice Control (EANC).
The EANC utilizes two digital microphones: the one next to the earpiece is called error microphone and the
other close to the main camera is called reference microphone.
The stereo IHF speakers are driven directly by a built-in stereo amplifier included in EM ASIC.
The vibra is driven directly by a built-in amplifier included in EM ASIC.
Bluetooth interface
Bluetooth provides a fully digital link for communication between a master unit (the phone) and one or more
slave units (e.g. a wireless headset). Data and control interface for a low power RF module is provided by the
BTHFM module.
Bluetooth is physically integrated with FM radio in the BTHFM module ASIC, but from a functional point of
view they have nothing in common
RM-424; RM-564
System Module
Issue 1
COMPANY CONFIDENTIAL
Page 6 –21
Copyright © 2009 Nokia. All rights reserved.
