PD178016GC-051_15 Datasheet, PDF (27/96 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
2.5.3 Momentary keys
The POWER key is effective even when pressed together with another momentary key. Pressing any other two
keys together is invalid, and it is assumed that no key has been pressed.
A BEEP sound (BEEP pin, pin 59) is output for 50 ms when a valid combination is pressed.
The functions of the momentary keys are described below (in alphabetical order).
Momentary key
Description
AUTO
This key is used to select the auto or manual mode.
This key is valid in radio mode.
Each time it is pressed, auto or manual mode is selected alternately.
In auto mode, the LCD indicator “AUTO” lights.
Manual mode is set in the initial state when the power is first applied.
The functions of the UP and DOWN keys differ depending on the selected mode.
• Auto mode
The UP / DOWN keys are used to start auto seek up/down operation.
• Manual mode
The UP / DOWN keys are used to start manual seek up/down operation.
BAND
This key is used to switch a band or to select radio mode.
(1) In radio mode
This key is used to select a band. The frequency of the selected band will be displayed. The LCD
indicator corresponding to the selected band (“FM1”/“FM2”/“FM3”/“MW”/”LW”) lights.
Each time this key is pressed, the band is changed as follows:
FM1 FM2 FM3 MW/LW
CDC
The FM1 band is selected in the initial state when the power is first applied.
The outputs of the BAND0 and BAND1 pins are changed depending on the selected band, as indicated
in the following table.
Band
FM
MW
LW
(0: Low, 1: High)
BAND0 pin (pin 24)
1
0
0
BAND1 pin (pin 25)
0
0
1
(2) In CD changer/tape mode
This key is used to select radio mode.
The frequency is displayed for two seconds then PS is displayed for three seconds (if there is no PS,
the frequency is displayed for five seconds). Subsequently, the display returns to normal.
The LCD indicator indicating the most-recently selected band (“FM1”/“FM2”/“FM3”/“MW”/“LW”) lights.
This key is used to select CD changer mode in radio or tape mode, and is used to play back or pause the
CD changer in CD changer mode.
(1) In radio/tape mode
Selects CD changer mode.
(2) In CD changer mode
Plays back or pauses the CD changer.
25