Filter
Top Products
Philips Semiconductors
User Manual of High-End RDS/EON
Car Radio System CCR612 (V0.3)
Application Note
96029
Key Description
AF
REGIONAL
When pressed short:
Switches AF follow mode on/off.
The state of the AF follow mode is displayed by the AF Icon:
Icon off: AF follow mode off
Icon on: AF follow mode on; RDS reception OK.
Icon blinking: AF follow mode selected, but no RDS data
received.
When AF follow mode is on, the radio will from time to time measure the
signal strength of the alternative frequencies that come with the RDS data.
The interval between measurements depends on the signal strength of the
current station, in the order of 1 minute for strong stations to a few seconds
for weak stations. When the radio finds an alternative frequency that is - in
several successive measurements - stronger than the current frequency, it
switches over to that frequency.
When pressed longer than 2 seconds (until the radio bleeps):
Toggles the regional on/off status displayed via an icon.
To check whether an alternative frequency is a real alternative for the
current station, the radio compares PI codes.
- Regional mode is on:
The PI codes must be exactly identical or a SUPRA regional variant.
- Regional mode is off:
The region identification code in the PI code is ignored.
When regional mode is off, the radio may switch to any programme service
carrying a PI code equal to the current PI code. In this case the regional
identification is not taken into account. When regional mode is on, the radio
will only switch to a programme service carrying exactly the same
programme. In both cases the radio may switch to transmitters broadcasting
in Supra-regional mode. For USA application (RBDS) the regional function
will only work for PI codes above B000
hex
. PI codes below B000
hex
do not
have regional variants. AF switching is only allowed to stations with exactly
the same PI code.
53