Fm Radio - Nokia RM-11 Series Troubleshooting Manual

CC Technical Documentation

FM Radio

FM radio circuitry is implemented using highly integrated radio IC (TEA5767HN) and is
controlled by the MCU software through a serial bus (GenlOS) interface.
Figure 15: FM Radio (N356) audio (N150), antenna, and digital interface connections
FM Radio Signal
FMWrEn
FMCtrlClk
FMCtrlDa
While 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 microcontroller writes the following bit. A tuning function starts when the write/
read signal changes from high to low. If a search tuning request is 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 level is
found, the tuning system stops and the Found Flag bit is set to high. If a band limit is
reached during the search, the tuning system stops at the band limit, the Band Limit flag
bit is set to high, and the Found Flag is set to high.
Issue 2 09/2005
Table 4: FM Radio Interface Timing
Min Max Condition
20µs t
wd
1 µs
t t
r/ f
50ms
t
start
14 µs
t
da
t
shift
10 µs
t
hold
1.5 µs
20 µs
t
setup
©2005 Nokia Corporation
Troubleshooting - Baseband
Note
FMWrEn high before rising edge of FMCtrlClk
(write operation)
rise/fall time
FMCtrlClk delay after switching on the VFLASH2
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)
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RM-11
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