PD178016GC-051_15 Datasheet, PDF (30/96 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
Momentary key
Description
MONO/LOC This key acts as a LOCAL/DX setting key when held down for at least two seconds. When released within
two seconds, it acts as a forced MONO ON/OFF key.
• ^{Forced MONO ON/OFF}
When an FM band is selected in radio mode, pressing this key switches forced MONO mode on or off. In
forced MONO mode, LCD indicator “MONO” appears. The “STEREO” indicator is forcibly turned off.
In forced MONO mode, MONO pin (pin 44) outputs a low level signal.
• ^{LOCAL/DX setting}
In radio mode, pressing this key switches the setting of LOCAL/DX.
In LOCAL mode, LCD indicator “LOC” appears, and the LOCAL pin (pin 23) outputs a high level signal.
The LOCAL pin outputs a high level signal, regardless of the setting, in auto-storage mode.
Forced MONO mode and DX setting are turned off in the initial state after the power is first applied.
POWER This key turns the power to the system on/off.
PSCAN/ASM
This key is used to perform auto-storage when it is held down for two seconds. When it is released within
two seconds, preset memory scan is performed.
This key is valid in radio mode.
• ^{For preset memory scan}
If a station other than a preset station is currently being received, the preset memory contents are
sequentially called for five seconds each, starting from M1, as shown below. If a preset station is currently
being received, the preset memory contents are sequentially called for five seconds each, starting from the
next station (for example, if M3 is currently being received, calling starts from M4).
M1 M2 M3 M4 M5 M6
When the next preset memory contents are called, a beep is issued for 50 ms.
During preset memory scanning, LCD indicator “PSCAN” appears. If there is a PS code, the PS code
blinks for three seconds after the frequency has been displayed, blinking, for two seconds. If there is no
PS code, the frequency is displayed, blinking, for five seconds.
• ^{For auto-storage operation}
During auto-storage, LCD indicator “ASM” appears.
At this time, the LCD panel switches to the frequency display.
Stations are searched from the lowest toward the highest frequency of the band currently being received.
The frequencies are written to the preset memory.
Searched stations are set to LOCAL in the first round of searching by the output signal of the LOCAL pin
(pin 23), and to DX in the second round. If six or more stations cannot be searched in the first round, the
second round of search is performed.
If a detected station is an RDS station, the PI code is also written to the preset memory.
If stations having the same PI code are detected during auto-storage, the signal meter values input from
S • METER (pin 3) are compared, and only that having the highest frequency is written.
Upon the completion of auto-storage, six of the detected stations are selected starting from that having the
highest signal meter value (RDS stations take precedence), and are written into preset memory, starting
from the station having the lowest frequency and starting from M1. If the number of detected stations is
less than six, the remaining preset memory locations remain as is, retaining the contents they had before
auto-storage was started. If search is aborted, all the preset memory locations retain the contents they
had before the start of auto-storage.
When TP/SK is on, only those stations broadcasting traffic information (stations with TP or SK) are
written.
28