JPH09172383A - On-vehicle radio receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To store new network information efficiently by selecting at random a write address and writing RDS data to the selected address in the case of writing the RDS data to a memory. SOLUTION: A microcomputer 4 receives RDS data (network information) from a PLL reception circuit 2 via an RDS data demodulation circuit 5 and stores the data to a memory 7 consisting of a RAM or the like. After the occurrence of network information to the memory 7, a network retrieval count value is set to a random value and network information write processing is conducted. The random value is selected to be a range not in excess of number of networks stored in the memory. Thus, the delete of a definite address somewhere without fail is prevented. That is, since the retrieval start position to the write area of the memory 7 is selected at random, new network information is written to the delete enable write area retrieved at first.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an RDS (Radio Dat).
a System) A vehicle-mounted radio receiver that performs an RDS function using data, and more particularly, to a vehicle-mounted radio receiver that has improved RDS data writing processing.

[0002]

2. Description of the Related Art Conventionally, RDS (Radio D
Ata System) Radio receivers that can receive data are widespread. This RDS data contains AF (Alternative Frequ
ency) data is included and the receiver can perform an AF search function based on this AF data.
This function is used in an on-vehicle radio receiver when a car moves out of the service area of a broadcasting station that is currently listening to another broadcasting program that has the same broadcasting program as the broadcasting station but has a different frequency. By entering the service area of a station, it is possible to automatically switch to the reception frequency of this other broadcasting station and continue listening to the same broadcasting program. Each RDS station transmits RDS data including, as an AF list, frequency data of network stations adjacent to the outer periphery of its own service area.

Also, the RDS station uses the PI together with the AF data.
(Program Identification) code and PS (Program Ser)
vice name) data is also sent. This PI code is
Data composed of a country code and a broadcasting station code and represented by four hexadecimal digits. For example, in the case of a network station,
Data with the same configuration for each station is sent. This PI code is
It is used for discrimination for not receiving the same frequency station different from the listening network station and for PI search when the AF broadcast cannot move to the next broadcast station. The PS data is data representing the name of the broadcasting station being received.
The receiver can receive RDS data (hereinafter referred to as a network) including AF data, PI code, and PS data and write it in a memory to perform various RDS functions by the network.

[0004]

However, in the conventional receiver, the writing process of the network to the memory is performed as shown in FIG.
As shown in the flowchart of FIG. 7, after the network writing in step S11 occurs, the network search counter value is set to the clear value (= 0) in step S12, and then the network writing process is performed in step S13. Therefore,
As shown in the memory writing area diagram of FIG. 4, the network search is performed by the network 1 of the memory writing position.
To the network Max (Max value depends on the memory capacity) are checked in order, so when the memory is full, a fixed network area such as the network 1 is always erased and a new network is written to the area. I was lost. That is, as an example, it is assumed that the user receives a new network by a tuner seek operation. This station is called station A. After that, if you operate the tuner seek again and set the received station as station B, the information of station A will be erased (station B will be written). Will be received as.

It is an object of the present invention to, in a vehicle-mounted radio receiver that performs the RDS function, when the network written in the memory is full, efficiently delete the previously written network to store the new network. It is to provide an in-vehicle radio receiver that can be used.

[0006]

A vehicle-mounted radio receiver according to the present invention is a vehicle-mounted radio receiver that receives RDS data and writes it in a memory, and performs various RDS functions based on the RDS data. When writing data in the memory, the writing position is randomly selected. Further, the means for randomly selecting the write position includes means for randomly setting the search start position of the write air in the memory, and means for writing new RDS station information in the writable area initially searched. . The RDS data is AF data, PI code and PS data.

[0007]

When the RDS data is written in the memory,
Randomly select the writing position and write. Therefore, the network in the predetermined area is not erased when the memory is full, and the new network can be efficiently stored.

[0008]

1 is a block diagram of an embodiment of a vehicle-mounted radio receiver of the present invention. In FIG. 1, 1
Is an antenna, 2 is a PLL receiving circuit, 3 is a muting circuit, 4 is a microcomputer (hereinafter referred to as a microcomputer), 5 is an RDS data demodulating circuit, 6 is a receiving sensitivity detecting circuit, 7 is a memory, 8 is a display, and 9 is PS (Program Servi
ce Name) indicator, 10 is a key input circuit. In FIG. 1, when a broadcast signal including RDS data from a broadcasting station is input from the antenna 1 to the PLL reception circuit 2, the microcomputer 4 causes the reception sensitivity detection circuit 6 to detect that the reception signal is S
The electric field strength seen by the meter output is 20 dBμV or more and IF
When the detection signal that satisfies the reception condition that the noise level at the output is 1.5 V or less is output, the muting circuit 3 is controlled to the inoperative state and the demodulated audio signal is output. However, if the reception condition is not satisfied, the detection signal is not generated from the reception sensitivity detection circuit 6, and the microcomputer 4 activates the muting circuit 3 to cut off the audio signal.

Further, the microcomputer 4 fetches RDS data (network) from the PLL receiving circuit 2 via the RDS data demodulating circuit 5 and stores it in a memory 7 composed of RAM or the like.
To memorize. The frequency display 8 displays the reception frequency under the control of the microcomputer 4, and the PS display 9 similarly displays the reception broadcasting station name under the control of the microcomputer 4. The key input circuit 10 can selectively cause each functional operation upon reception by a predetermined key operation.

FIG. 2 is a flow chart for explaining the operation of the block diagram of FIG. First, after network writing to the memory 7 occurs in step S1, the network search counter value is set to a random value in step S2, and then network writing processing is performed in step S3. This random value is within a range that does not exceed the number of networks (memory Max value in FIG. 3) held in the memory. For example,
When the network Max value is 5, it has the network information such as ,,,, but it was searched in order until now ,,,,,
The search start point is randomized, such as the order of ,,,,,.

Therefore, for example, the network information is
In the case of "erasable, erasable, erasable, erasable, erasable", by randomly setting the start position, it is possible to prevent erasure of a certain place. (In the conventional method, it is inevitably erased.) That is, since the search start position for the write area of the memory 7 is randomly selected, new network information is written in the erasable write area searched first. Is written. As described above, in the present invention, the writing position of the newly stored network becomes random, so that the network information (AF data, PI code, PS data) can be effectively used.

[0012]

According to the on-vehicle radio receiver of the present invention, the effect is exhibited when the memory is full of network information. In particular, a great effect can be obtained by using the present invention in an on-vehicle radio receiver having a small memory capacity. When writing new network information, it is possible to prevent the deletion of a fixed network, so that the network information can be effectively used.

[Brief description of the drawings]

FIG. 1 is a block diagram of an embodiment of a vehicle-mounted radio receiver according to the present invention.

FIG. 2 is a flow chart illustrating operation of the block diagram of FIG. 1 according to one embodiment of the present invention.

FIG. 3 is a flowchart illustrating an operation of a conventional vehicle-mounted radio receiver.

FIG. 4 is a writing area diagram of a memory of a conventional in-vehicle radio receiver.

[Explanation of symbols]

 1 Antenna 2 PLL Reception Circuit 3 Muting Circuit 4 Microcomputer 5 RDS Data Demodulation Circuit 6 Reception Sensitivity Detection Circuit 7 Memory 8 Frequency Display 9 PS Display 10 Key Input Circuit

Claims (3)

[Claims] 1. In a vehicle-mounted radio receiver that receives RDS station information and writes it in a memory and performs various RDS functions according to the RDS station information, when writing the RDS station information in the memory, a write position is set. An in-vehicle radio receiver having means for selecting at random. 2. The in-vehicle radio receiver according to claim 1, wherein the means for randomly selecting the writing position is means for randomly setting the search start position of the writing area of the memory, and the first searched writing. An on-vehicle radio receiver including means for writing new RDS station information in the coverage area. 3. The in-vehicle radio receiver according to claim 1 or 2, wherein the RDS station information is AF data, PI code and PS data.