User Guide

RM-11
Troubleshooting - Baseband CC Technical Documentation
Page 30 ©2004 Nokia Corporation Confidential Issue 1 02/2004
FM Radio
FM radio circuitry is implemented using a highly integrated radio IC (TEA5767HN). The
MCU SW controls FM radio circuitry through a serial bus (GenlOS) interface.
Figure 26: FM Radio (N356) Audio (N150)-, antenna- and digital interface connections
Table 10 shows the FM radio interface timing for the FMWrEn, FMCtrlClk, and FMCtrlDa
radio signals.
While the WRITE/READ is HIGH, the microcontroller can transmit data to the TEA5767.
At the rising edge of the Bus clock, the register shifts and accepts the stable bit. At clock
LOW the micro controller writes the following bit. A tuning function is started when the
WRITE/READ signal changes from HIGH to LOW. If a search tuning request was sent, the
IC autonomously starts searching the FM band. The search direction and search stop
level can be chosen. If a station with a field strength equal to or higher than this stop
Table 10: FM radio interface timing
FM
Radio
Signal
Min Nom Max Condition Notes
FMWrEn 20µst
wd
FMWrEn high before rising edge of FMCtrlClk
(write operation)
FMCtrlClk
50ms
1 µst
r/
t
f
t
start
Rise/fall time
FMCtrlClk delay after switching on the VFLASH2
FMCtrlDa
10 µs
1.5 µs
20 µs
14 µst
da
t
shift
t
hold
t
setup
Shift register available after “search ready”
Data available after FMCtrlClk rising edge
(read operation)
FMCtrlDa stable after FMCtrlClk rising edge
(write operation)
FMCtrlDa set before FMCtrlClk rising edge (write
operation)
FM Radio
UPP
HSEARN
HSEARP
HSEARRN
HSEARRP
68nH
40pF
100P
Stereo
audio
Amplifier
TOMAHAWK
System Connector
Antenna signal
Genio(24)
Genio(12)
Genio(18)
Genio(6)
Xtal1
Data
W/R
Clock
Rfin1
Audio R
Audio L
FMClk
FMCtrlDa
FMCtrlClk
FMWrEn