Fm Radio Interface - Nokia RM-627 Service Manual

RM-627
System Module
Figure 42 Bluetooth interface
The BTHFM module is powered by the regulated voltage VIO. For audio applications the Bluetooth has a PCM
data bus. In addition an UART (universal asynchronous receiver/transmitter) is used for data communication
and controls.

FM radio interface

The FM radio system is controlled by RAPU via the I2C bus. EM ASIC delivers the needed voltages and the clock
reference (32.768kHz SleepClk). EM ASIC also processes the analog audio.
The FM receiver fully supports reception over US/European (87.5MHz to 108MHz) and Japanese (76MHz to
90MHz) FM band. The FM receiver comprises an RF receiver with fully integrated VCO, a stereo FM demodulator
and a RDS demodulator.
A headset accessory is used as an external antenna. The headset is connected to the AV connector.
FM radio is physically integrated with Bluetooth in the BTHFM module ASIC, but from a functional point of
view FM radio and Bluetooth have nothing in common.
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