PD17012GF-055_15 Datasheet, PDF (16/84 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
2.4 Description of Key Matrix
2.4.1 Initialize diode matrix
The initialize diode matrix contains the following 18 types (43 items). All these types are read only when the power
is initially turned on (power-ON reset) to the VDD pin on when the CE pin is changed from low level to high level. At
other times, they are ignored.
(1) Switch for setting the method of detecting broadcasting stations in auto tuning.
FM SD/IF, AM SD/IF
(2) Switch for setting the intermediate frequency of the AM band
AMIF1, AMIF2
(3) Switch for setting clock functions
CLK24, FLASH, NOCLK, CLKDSP
(4) Switch for selecting between ON/OFF of auto retune
RETUNE
(5) Switch for setting the
ME
key
MESEL
(6) Switch for selecting whether a priority display should be made
PRIDISP
(7) Switch for selecting electronic volume source switching
VOLFUNC
(8) Switch for selecting the tuning mode
PRIMANU
These switches are set on the matrix after short-circuiting it with diodes.
Functions of the initialize diode matrix are described on the following pages. For the diodes, “1” indicates short-
circuited; and “0” indicates open.
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