PD178016GC-051_15 Datasheet, PDF (49/96 Pages) Renesas Technology Corp – 8-BIT SINGLE-CHIP MICROCONTROLLER WITH BUILT-IN PRESCALER, PLL FREQUENCY SYNTHESIZER, AND IF COUNTER FOR AUTOMOTIVE FM/MW/LW RADIO APPLICATIONS

µPD178016GC-051
(2) Operation of best station
(a) One station is received at a time in steps <1> through <5>, below, starting from the beginning of the AF list,
and the signal meter reading for each station is measured.
<1> Mute is turned on, and the LPFSEL pin (pin 27) is driven high after the completion of the preceding mute
time (3 ms).
<2> A channel on the AF list is received.
<3> The signal meter reading is measured using the S • METER pin (pin 3), 1 ms after the station has been
locked.
If the station is not locked after 40 ms, and if the signal meter reading is less than that when best station
was started, or if it is less than the best station start condition, <5> is performed.
<4> The input signal meter reading is stored into RAM.
<5> The above operation is repeated starting from <2> if there is another station to be checked.
(b) PI check is sequentially performed starting from the greatest of the signal meter readings measured in (a).
<1> A channel on the AF list is received.
<2> The signal meter reading is measured by using the S • METER pin, 1 ms after the station has been
locked.
If the station is not locked after 40 ms, and if the signal meter reading is less than that when best station
was started, or less than the best station start condition, <8> is performed.
<3> IF is measured 5 ms after if initial setting diode FM SD/IF is jumpered.
If IF is not within the permissible range, <8> is performed.
<4> The LPFSEL pin is driven low.
<5> Reading PI is awaited.
If decoding is not performed once within 400 ms, <8> is performed.
If decoding is not performed two times within 800 ms, <8> is performed.
<6> The read PI code is checked for coincidence.
For an explanation of how to check the PI code, see (4) in Section 3.1.5.
<7> If the PI code coincides, that station is received, and best station is completed.
<8> If there is another station to be checked, the above operation is repeated starting from <1>.
<9> If no station is found after all the frequencies on the AF list have been searched, best station is
terminated, and PI seek is performed.
3.1.7 Automatic station selection
A search is made for a station by using the RDS data during seek.
The following four types of seek operations can be performed.
(1) RDS seek
(2) PI seek
(3) PTY seek
(4) TP/SK seek
(1) RDS seek
• RDS seek is performed if seek is performed in RDS mode.
• Only an RDS station is selected from the stations that are judged to have a station.
• RDS seek is terminated if the following condition is satisfied.
(a) If a PI code is read within 650 ms after the existence of a station has been judged.
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