User Guide

6255/6255i6256/6256i (RM-19)
Baseband Description and Troubleshooting Nokia Customer Care
Page 30 ©2005 Nokia Corporation Company Confidential Issue 2 05/2005
FM Radio
FM radio circuitry is implemented using highly integrated radio IC, TEA5767HN. FM radio
circuitry is controlled through the serial bus (GenIOs) interface from MCU SW.
Figure 18: FM Radio (N356), Audio (N150), antenna, and digital interface connections
Stereo audio output signals are fed to the stereo amplifier. Volume control of the FM
audio signal is made by circuitry inside the amplifier. The amplified audio signal is fed to
the headset or IHF speaker. The headset is also used as an antenna input for the radio.
FM Radio Test
To hear the FM radio, connect the headset to the Pop-port or UHJ ports because the
headset is the FM radio antenna. Also, connect the headset to an UHJ port to control the
FM radio using Phoenix. However, if you connect a headset (e.g., HDS-3) to a Pop-port
connector, then you cannot control the mobile terminal because you have already
occupied the connection port (Pop-port). In this case you have to have jumper wires on
the production test points (Fbus Tx/RX, GND).
Input Signals to the FM Radio
After connecting a headset to the UHJ port to control the mobile terminal through
Phoenix, you can see the following signals by turning on the FM radio in Phoenix (which
is in the RF menu).
Check the following signals to see whether they are changed as represented in Figure 19:
• FMClk = Test Point (FM04) : 32KHz/1.8V
• FMWrEn = Test Point (FM03) : Write enable at 1.8V
• FMCtrlClk = Test Point (FM02) : Control clock at 1.8V
• FMCtrlDa = Test Point (FM01) : Control data at 1.8V