PD17012GF-055_15 Datasheet, PDF (53/84 Pages) Renesas Technology Corp – SINGLE-CHIP MICROCONTROLLER WITH ON-CHIP PRESCALER, PLL FREQUENCY SYNTHESIZER, AND IF COUNTER FOR CAR-MOUNTED FM/MW/LW RADIO

µPD17012GF-055
6.1.7 AF switchover
There are two types of AF switchover operations.
(1) AF switchover of all stations at once (refer to Figure 6-7)
(2) AF switchover of a station at a time (Interval 5 seconds (refer to Figure 6-8))
The timing charts of the respective operations are shown below and on the following page.
For conditions for occurrence of the AF operations, please refer to 5.2.4 AF (Alternative Frequency).
(1) All-Station AF switchover at once
Figure 6-7. Timing Chart for All-Station AF Switchover
MUTE
2
2 ms
34 5
6
4 ms
745
6
7
4 ms
1
45
8
200 ms
N value set for
the strongest SD
station
PI code
coincidence
1 Occurrence of AF switchover condition
2 MUTE first-out wait
3 SD sort (Stations with SD are determined beforehand on the AF list and sorted in the order of the
frequency.)
4 Frequency division ratio setting
5 PLL lock wait
6 SD judgment wait
7 SD level comparison
8 PI code input, judgment wait
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