JPH04119785A - Teletext receiver - Google Patents

Abstract

PURPOSE:To index a data having no reception error without a waiting time by deleting a page data discriminated to have a data error, retrieving an old page data stored in a page memory at indexing and writing a data received newly to a deleted memory area. CONSTITUTION:When a packet data with a registered program number (0/010#) is stored in a buffer memory, the data is sequentially stored in address areas of a memory '1'. Since it is discriminated that an error exists in a total page number at the end of reception of a 2nd page data whose page is 02, relevant areas are deleted and a data whose page 03 received succeedingly is stored in succession to the page 01. Thus, when the page 02 is indexed at that point of time, the data stored in the 1st storage time is retrieved. When a new data is received in the buffer memory, error correction processing is implemented to the reception data stored in the buffer memory and when a reception error exists, the data of relevant page data areas is deleted and the head address of the deleted addresses is used as a write start address of a succeeding page data.

Description

[Detailed Description of the Invention] [Purpose of the Invention (Field of Industrial Application) The present invention relates to a teletext receiving device equipped with a page memory that stores programs in page units, and in particular, to a teletext receiving device that can perform page search operations smoothly. The present invention relates to a teletext receiving device.

(Prior Art) Teletext broadcasting is a system that repeatedly transmits many types of teletext programs in the form of digital signals during a specific horizontal scanning period of a vertical blanking period of a television signal. The receiving side is equipped with a buffer memory for capturing teletext data.
The teletext data is sequentially written into the buffer memory, and when the receiver specifies the program number of the desired program using a means such as a keyboard, the specified program is searched from the buffer memory and the program is continued. The data of the program can be transferred to the display memory and presented.

In such a receiving system, as the number of programs increases,
The problem was that it took a long time to transmit all the programs, and the waiting time until a designated program was presented on the screen became long. Therefore, conventionally, a page memory is provided to store teletext data for multiple sides, and programs desired by recipients are stored in the form of program number registration, thereby eliminating waiting time.

FIG. 4 is a memory map showing the operation of the page memory. FIG. 4(a) shows the order in which teletext data is received (the order in which it is held in the buffer memory). Now, program number 01012,01013゜01014.01015
．． When registering programs, the data of each registered program is held in the page memory in the order in which it is received one page at a time, as shown in FIG. 4(b). Then, as more time passes, the page memory is rewritten into a pig as shown in FIG. 4(C). The thick line represents the time of this rewriting. Therefore, the program reserved in the page memory at each rewriting time can be presented without waiting time. In addition, in the case of a program with a multi-page structure,
Even if the entire program is not stored in the page memory, the stored part will be presented without waiting time, and if the data of the unregistered page is transmitted during that time, the entire program will be presented without waiting time. Can be received and presented.

On the other hand, the character multiplexed signal written in the buffer memory is subjected to processing such as error correction. At this time, since the character multiplex signal determined to be a signal error is not stored in the page memory, it is stored in the page memory as incomplete page data with some data missing. Therefore, there is a problem in that when the missing page data is presented, it is not presented correctly and only incomplete pages can be presented to the recipient.

(Problems to be Solved by the Invention) As described above, in the past, incomplete page data with some data stored in the page memory missing may be presented due to an error in receiving a character multiplex signal. This resulted in a complete and unsightly page, and in order to present a page without errors, it was necessary to wait until the next same page without errors was received again.

Therefore, the present invention is intended to improve the above problem.Page data that is determined to have a data error in the page memory is erased, and when presenting that page, the old page data stored in the page memory is deleted. It is an object of the present invention to provide a teletext receiving device that searches and presents data, and writes newly received data in the erased memory area.

[Structure of the Invention] (Means for Solving the Problems) The present invention has a page memory that captures teletext data and stores it in page units, and programs registered in the page memory by specifying a program number. In a teletext receiving device that transfers data to a display memory and presents it, means for counting the total amount of data in units of pages of programs stored in the page memory, and means for determining whether there is an error in the total amount of page data based on the counting result. and a means for erasing the page data determined to have a total amount of page data error based on the discrimination result, and a means for writing newly received data from the erased page memory area, so that the page data without any reception errors is provided. This is what we provide.

(Operation) In the present invention, only page data without reception errors can be stored in the page memory, and when an error is detected in the received page data, the same page data stored in the page memory can be detected and presented. By doing so, it becomes possible to present programs without waiting time and without errors.

(Example) Hereinafter, the present invention will be explained based on illustrated embodiments.

FIG. 1 is a block diagram showing an embodiment of a teletext receiving apparatus according to the present invention.

In FIG. 1, 11 is a television antenna, 12 is a tuner, and 13 is a video detection circuit.The high frequency signal induced in the antenna 11 is received by the tuner 12 as an intermediate frequency signal of a desired channel, and the output of the tuner 12 is The signal enters the video detection circuit 13 and is detected. Note that the tuner 12 is controlled by a tuning voltage from the channel selection control circuit 14 so as to receive a signal of a desired channel.

On the other hand, 15 is a data acquisition circuit that extracts teletext data, corrects errors, and then holds it for a period of time, and has a buffer memory for temporarily holding the extracted teletext data. An output end of the data acquisition circuit 15 is connected to a data bus 19.

CPtJ16. RAM17. and the ROM 18 searches for data held in the buffer memory (reception processing).
, a central processing circuit that executes presentation processing and the like.

20 is a display control circuit controlled by CP016. The 0 display control circuit 20 receives the program data of the desired program number detected by the search process from the data acquisition circuit 15, presents the transferred data, and displays it. The data is written into the memory 21 and the written data is displayed in a predetermined period. Reference numeral 22 denotes a keyboard such as a remote control, and inputs key manual data for receiving a desired channel by operating predetermined keys to the channel selection control port B.
The program number of the teletext broadcast to be supplied to or received by the CP IJ 14 is supplied to the CP IJ 16.

Reference numeral 23 denotes a page memory composed of a memory that stores a large number of pages. This page memory 23 is
Control is performed to store data for each teletext program, and each program data is written into a predetermined program memory area. Furthermore, programs can be registered separately for each channel. In addition, the RAM 17
A registration area for program numbers and reception channel data broadcasting the program is provided corresponding to each program memory area. These reception channel data and program number data can be input by key operations from the keyboard 22.

FIG. 2 is an explanatory diagram for explaining the write operation of the page memory 23. In FIG. 2, (a) shows the reception order of program data, and (b) shows a map of program memory "1". Although the page memory 23 has an area for storing n (n is any integer) programs, the page memory 23 according to this embodiment shows only the operation of memory "1" here. The entire area is divided into n program memory areas, and each divided area memory "1", memory "2", memory "3", memory "4" for each program of teletext data.
. . . Programs to be stored in each memory using memory "n" are registered in advance by number designation by operating the keyboard 22, and when the designated program is received, the program is stored in each memory. starting address, superimposed H data, service identification (SI) data, total page number data (DOS
) is stored in the RAM 17, and subsequently received page data is stored in the corresponding page memory. When there is no free space in each memory, the process returns to the beginning of the memory area and stores the latest page data.

Here, the total page number data (D
GS) is subtracted each time it is written to each page memory, and when the last page data is received or the beginning of the next page data is received, the total page number data (DGS) is Determine if there is, r
When it is OJ, it is determined that there is no reception error in the stored page unit, and when it is 1 other than rQ, it is determined that there is a reception error in the stored page unit. For the page data that is determined to have received errors in page units, the page area is erased from the start address of the page stored in the RAM 17, and the next page data to be received is stored from the start address.

To explain specifically, memory “1” of the page memory 23
Program number 01010# is registered in . This program is registered in advance by specifying a number by operating the keyboard 22. When the packet data of the registered program number (01010#) is held in the buffer memory, the memory "
1" address area. In FIG. 2, (a
) is shown in (b) of the data stored in the memory "1" at the reception point (2). In (b), when the second page data reception of page o2 was completed, it was determined that there was an error in the total number of pages, so the corresponding area was erased, and page 03, which was received next, was stored following page 01.9 Therefore, when presenting page 02 at this point, the data stored the '1st time is retrieved.

Here, whether or not the packet held in the buffer memory of the data acquisition circuit 15 is a registered program is determined by the CPU based on data identification data such as a program data header (PRCI) and a page data header (PACI).
16 has been identified.

The third section is a flowchart showing the page data storage operation performed by the CPU 16 in FIG. When new data is received in the buffer memory (step S1:
YES) In step s2, error correction processing is performed on the received data stored in the buffer memory, and it is determined that there is no error (step S3: NO>, the contents of the buffer memory are changed to data identification data (PRC1, P
ACI), and if it is data identification data, select S
In step S5, it is determined whether the program number in the data identification data is a registered program, and if it is a registered program, the RAM 17 is
The total number of page data in the corresponding memory held in the DGS
) is rQJ. If r OJ (No>, the process goes to step S9; if it is 1 other than 0, the process goes to step S8.

Step S8 indicates a reception error in the total number of previously stored page data, and the data in the corresponding page data area is erased, and the erased top address is set as the next page data write start address. Here, the corresponding page data area is R
From the write start address held in AM17 to the address where the final data is stored.

In step S9, write address data at the top of the page, superimposed H data, and service identification data are stored in the RAM.
It is held in the corresponding area of 17.

In step S10, the received data in the buffer memory is written into the corresponding area of the page memory.

In step Sll, update the page memory write address and add 1 to the total number of page data (DGS).
8=DO3-1) Store in RAMI 7.

In step S6, if there is a page memory being stored,
The superimposed H data and service identification data held in the RAM 17 are compared with data identification data other than the received registered program, and if the data match, the corresponding superimposed H data and service identification data held in the RAM 17 are , and interrupts write operations to page memory.

In step S12, a page memory that matches the buffer memory in which the superimposed H data and service identification data of each page memory stored in the RAM 17 are received is searched,
If there is a corresponding page memory, the process advances to step SIO.

In addition, if new data is not received in step S1, if there is an error in step S3, or if there is no corresponding page memory in step S12, furthermore, if there is no corresponding page memory in step S12,
After the processing in Step 6 or Step Sll is completed, the process returns to the start and the reception standby state is entered.

[Effects of the Invention] As described above, according to the present invention, data without reception errors is always stored in the page memory, and it is possible to present data without reception errors without waiting time.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the teletext receiver according to the present invention, FIG. 2 is a memory map for explaining the write operation of the page memory shown in FIG. 1, and FIG.
In the figure, there is a flowchart showing the write operation of the page memory, and FIG. 4 is a memory map explaining the operation of the conventional page memory. 15...Data acquisition circuit, 16...CPU, 17
...RAM, 18...ROM, 19...data bus, 20...display control circuit, 21...display memory, 22...keyboard, 23...page memory (a) No. Figure 3 (a) Figure 4

Claims (1)

[Scope of Claims] It has a page memory that captures teletext data transmitted during a predetermined period of a vertical retrace period in a television broadcast signal and stores it in page units, and by specifying a program number, A teletext receiving device that transfers program data registered in a memory to a display memory and presents the same, comprising means for counting the total amount of data in units of pages of programs stored in the page memory, and detecting errors in the total amount of page data based on the counting results. means for determining the presence or absence of page data; means for erasing page data determined as having a total amount of page data error based on the discrimination result; and means for writing newly received data from the erased page memory area. A teletext receiving device characterized by presenting error-free page data.