Tv-Out Interface; Consumer Infrared Transmitter (Cir); Audio Concept; Audio Hw Architecture - Nokia N900 Service Manual

RX-51
System Module

TV-out interface

This device has an analog composite TV-out feature. TV-out signal is received straight from the OMAP's
dedicated TV-out output. It is then routed via a switch to an AV-connector. There it can be transferred to the
TV with a composite cable with a 3.5 mm plug.

Consumer infrared transmitter (CIR)

The device also has an infrared transmitter that can be used as a remote control. It is made by using a high
power IR LED. Transmissions are made with GPIO that is modulated with the right frequency.

Audio concept

Audio HW architecture

The device audio hardware is built around AIC34 audio codec. AIC34 contains two individual audio codecs
which are improved versions of AIC33 codec. AIC34 codec partitions are named A and B, which are referenced
in this document as AIC34_A and AIC34_B. OMAP is connected to AIC34_A. AIC34_B is used to amplify earpiece
signal and to provide bias voltage for AV-interface microphone. There are no digital or analog audio
connections inside AIC34 between partitions A and B, so the partitions are connected using external signal
routing.
The top level audio architecture and audio hardware block diagrams are presented in the figures below.
Figure 56 Top level audio architecture
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