KR100670405B1 - A method for managing digital audio broadcasting data using nand flash memory - Google Patents

Abstract

A method for managing digital audio broadcasting data by using a NAND flash memory is provided to prevent stored DAB audio data from being copied to the other device by using a hidden area of the NAND memory that a general user can not access, thereby safely protecting the data. A method for managing digital audio broadcasting data by using a NAND flash memory comprises the following steps of: making a digital audio broadcasting signal received to a broadcasting receiver from a DAB(Digital Audio Broadcasting) radio station(S100); extracting the digital audio broadcasting data from the received digital audio broadcasting signal; setting a circular ring buffer, having a block unit data structure, in the NAND memory; setting a write start point of the circular ring butter to be suitable for a block boundary of the circular ring butter; setting a write buffer having a multiple size of a block change prevention write unit to write the data on the circular ring butter; and storing the extracted digital audio broadcasting data in the write butter(S200).

Description

A method for managing digital audio broadcasting data using NAND flash memory}

1A is a block diagram schematically illustrating a configuration of a DAB terminal in a digital audio broadcasting data management method using a NAND flash memory according to an embodiment of the present invention;

FIG. 1B is a diagram illustrating in detail the configuration of a memory unit of a DAB terminal in a digital audio broadcasting data management method using NAND flash memory according to an embodiment of the present invention; FIG.

2 is a flowchart schematically showing a method for managing digital audio broadcast data using a NAND flash memory according to an embodiment of the present invention;

3 illustrates a process of deleting existing data while digital audio broadcast (DAB) data is stored in a circular ring buffer in a digital audio broadcast data management method using a NAND flash memory according to an embodiment of the present invention. Shown,

FIG. 4 is a diagram showing the structure of a block-by-block NAND memory in a digital audio broadcasting data management method using a NAND flash memory according to an embodiment of the present invention; FIG.

FIG. 5A illustrates an operation performed in a circular ring buffer that is not full in a digital audio broadcasting data management method using a NAND flash memory according to an embodiment of the present invention; FIG.

FIG. 5B is a view showing an operation performed in a circular ring buffer filled in the digital audio broadcasting data management method using NAND flash memory according to an embodiment of the present invention; FIG.

6 illustrates digital audio broadcast data in a NAND hidden memory using a write buffer and a read buffer in a method of managing digital audio broadcast data using a NAND flash memory according to an embodiment of the present invention. A drawing showing the process of saving or reading a file,

7A is a diagram illustrating a problem that occurs when decoding an error data in a digital audio broadcasting data management method using a NAND flash memory according to an embodiment of the present invention;

FIG. 7B is a diagram illustrating that a problem occurring when decoding an error data in a method of managing digital audio broadcasting data using a NAND flash memory according to an embodiment of the present invention is solved through a forced time interval cleanup.

<Description of the symbols for the main parts of the drawings>

10: broadcast receiving unit 20: key input unit

30 control unit 40 memory unit

50: audio decoder

The present invention relates to a digital audio broadcast data management method using a NAND flash memory, and more particularly, to store digital audio broadcast data by storing the digital audio broadcast data in a hidden area of a NAND memory which cannot be used by a general user. The present invention relates to a DAB data management method that can be efficiently managed.

Digital radio broadcasting called DAB is a digital broadcasting that replaces the existing analog broadcasting, and is an air broadcasting that transmits compressed audio data and digital information necessary for broadcasting instead of analog data.

To record a previous radio station, the analog interpreted sound can be converted to PCM via AD and stored digitally, compressed or uncompressed, or recorded on audio tape using the previous method. The stored data can be listened to by the user repeatedly or selected.

In the case of DAB instead of conventional radio, since the received data includes compressed audio data, it provides higher quality data than conventional radio. There is a problem in that the performance of the device must be high due to exhaustive operation.

In addition, when it is necessary to guarantee the sound source with DRM (copyright-protected digital certification), it is illegal to store or use high quality DAB broadcasting data as it is. Therefore, devices with high capacity NAND memory need to manage DAB broadcast data more efficiently.

Accordingly, the present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to use a high capacity NAND memory to store DAB data for an hour or more, so that the audio device can be forwarded and rewound. It provides a function such as, and to facilitate the user by enabling the use of random access, which is an advantage of digital devices.

In addition, an object of the present invention is to provide a function to ensure the safety of the data and to protect the copyright of the data by storing the DAB data stored in the NAND hidden area inaccessible to the general user.

Digital audio broadcast data management method using the NAND flash memory of the present invention for achieving the above object comprises the steps of a broadcast receiving unit receiving a digital audio broadcast signal from a DAB radio station; The digital audio broadcasting data is extracted from the received digital audio broadcasting signal and stored in a circular ring buffer having a block unit structure in a hidden area of a NAND memory, and the extracted data is stored in the circular ring buffer. Stored in sequence; And reproducing the digital audio broadcast data according to an operation of a key input unit.

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Hereinafter, a digital audio broadcasting data management method using a NAND flash memory according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

<Configuration of DAB terminal>
1A is a block diagram schematically illustrating a configuration of a DAB terminal in a digital audio broadcasting data management method using a NAND flash memory according to an embodiment of the present invention.

The broadcast receiver 10 functions to receive a digital audio broadcast signal received from a DAB radio station.

The key input unit 20 includes a plurality of key inputs for receiving digital audio broadcasting (DAB), such as power on / off, channel selection, volume, MP3 playback, fast forward and rewind.

The controller 30 functions to generate control signals between the broadcast receiving unit 10, the key input unit 20, the memory unit 40, and the audio decoder 50 to collectively control each component.

The memory unit 40 functions to store digital audio broadcast data extracted from the digital audio broadcast signal received through the broadcast receiving unit 10. A more detailed configuration of the memory unit 40 is shown in Fig. 1B.

FIG. 1B is a diagram illustrating in detail the configuration of a memory unit of a DAB terminal in a digital audio broadcasting data management method using a NAND flash memory according to an embodiment of the present invention.

As shown, there is an area formed of NAND memory in the memory unit 40, and the NAND memory is further divided into a file system area 41 and a NAND hidden area 42. In the case of using a storage device other than NAND, it is impossible to obtain an economical performance with appropriate performance speed and storage capacity. Since the NAND hidden area 42 is an area that is not available to the general user, the data can be secured. In the present invention, the digital audio broadcast data is stored in the hidden area 42 of the NAND memory.
More specifically, the digital audio broadcast data is stored in a circular ring buffer which is located in the hidden area 42 of the NAND memory and has a circular structure of a limited size and a block unit structure. The data is stored continuously, and if there is existing data stored, new data is stored at the same time.

The audio decoder 50 functions to decode digital audio broadcast data stored in the hidden area 42 of the NAND memory. The digital audio broadcast data is first stored in a read buffer and then decoded through the audio decoder 50 and then reproduced.

<How to manage digital audio broadcast data>
2 is a flowchart schematically illustrating a method for managing digital audio broadcast data using a NAND flash memory according to an embodiment of the present invention.

First, the broadcast receiving unit 10 receives a digital audio broadcast signal from a DAB radio station (S100).

Then, the digital audio broadcast data is extracted from the received digital audio broadcast signal and stored in the hidden area 42 of the NAND memory. At this time, the digital audio broadcast data is located in the hidden area 42 of the NAND memory and is sequentially stored in a circular ring buffer having a cyclic structure and a block unit structure of a limited size. That is, the digital audio broadcast data is continuously stored in the most recent data stored in the circular ring buffer, and if there is existing stored data, new data is stored at the same time (S200).

Then, the digital audio broadcast data is reproduced according to the operation of the key input unit 20 (S300).

<Buffer Data Structure for DAB Broadcast Reception>
If the size of the DAB broadcast can be stored as 1 hour, the 1 hour time constraint means that the amount of past stored data is 1 hour from the last received data. This means that after 10 minutes, 10 minutes of data is lost an hour ago.
The area where the DAB broadcast is stored is one hour from the present to the past, and data also flows as time passes, so the currently received data has a time allowance to be handled for the next hour. This storage of a certain amount of data as a reference of the current data is referred to as "moving buffering (Moving Buffering)". This is because the data stored in the buffer flows from the present to the past.

3 illustrates a process of deleting existing data while digital audio broadcast (DAB) data is stored in a circular ring buffer in a digital audio broadcast data management method using a NAND flash memory according to an embodiment of the present invention. The figure shown.

As shown in the drawing, when data is received from the DAB and stored, the data should be read out when the DAB audio buffer is full. Since the data structure that controls the block of NAND memory has the structure of a circular ring buffer, when all blocks are stored, the oldest data is discarded and new data is stored in place.

In addition, the digital audio broadcast data is recorded in a recording unit (hereinafter, referred to as a block conversion prevention recording unit unit) that does not cause a block change in a block of the circular ring buffer, and the digital audio broadcast data is stored. The recording start position of the circular ring buffer is set in accordance with the block unit of the circular ring buffer.

Although the time taken to write data to NAND memory is generally similar, when the block change occurs, which is a characteristic of NAND memory, it has a slow operation time writing speed, so that broadcast data must be stored in time. Implementation may not be possible. Therefore, in order to efficiently read and write data in the hidden area of the NAND memory, a block change, which is a characteristic of the NAND, must be prevented from occurring.

Realization of data structure utilizing characteristics of NAND block
4 is a diagram showing the structure of a block-based NAND memory and a recording start position in a digital audio broadcasting data management method using a NAND flash memory according to an embodiment of the present invention.

As shown, NAND has a block size, and the size of every NAND company varies. Block change occurs when a write needs to be written in the area between blocks and blocks, so the NAND Hidden start point (Buffer start point) is used in units of blocks.

FIG. 5A illustrates an operation performed in a circular ring buffer that is not full in the digital audio broadcast data management method using NAND flash memory according to an embodiment of the present invention.

As shown, Case 1 has a sufficient buffer size to store. Since the user must save and read data while listening to the broadcast, the reading and writing locations are pointing to the same place, and the user has not done anything.

In case 2, the size of the stored buffer is increased over time than case 1. At the request of the user, the player rewinds while listening to the broadcast, and attempts to read data from previous data. In Case 2, data stored in the past can be heard by the user, while data currently being broadcast is continuously stored in the record pointer.

FIG. 5B is a diagram illustrating an operation performed in a circular ring buffer filled in the digital audio broadcast data management method using NAND flash memory according to an embodiment of the present invention.

As shown, in Case 3, it can be seen that all the buffers are stored and used, and the read and write positions are the same. Due to the nature of the circular ring buffer, when the buffer is used up, the oldest data is used, so the position of read and write is returned to the beginning of the buffer. In this case (Case 4), the data on the left of the read and write position is the most recent and the right is the oldest.

Case 5 is full, so you can read it anywhere. Since all data before the read point is in the past, random access is possible except for data discarded by new data.

In addition, the memory unit 40 of the DAB terminal includes a write buffer having a multiple size of the block conversion prevention recording unit described above, and the extracted digital audio broadcast data is first stored in the recording buffer and then the circular ring buffer. Are written in units of block conversion prevention recording units.

<Processing and storing data obtained from the buffer>
6 illustrates digital audio broadcast data in a NAND hidden memory using a write buffer and a read buffer in a method of managing digital audio broadcast data using a NAND flash memory according to an embodiment of the present invention. A diagram illustrating a process of saving or reading a file.

As shown, the circular ring buffer for storing DAB data is located in the hidden area of the NAND memory and has a data structure in units of blocks. As described above, the recording structure of the block conversion prevention recording unit unit is required, and the unit is expressed as 'Write size' in FIG. The high-capacity NAND memory currently available has a size of 4 kbytes. Although the DAB differs depending on the broadcast mode, one compressed audio data is transmitted about every 24 msec.
Since there is a unit used for writing, a buffer that is waiting until the broadcast data to be transmitted becomes a size that can be stored is called a write buffer. The size of the write buffer is set in multiples of the write size (block conversion prevention write unit unit).
In the case of the read operation, it is not necessary to consider such a block change. Because frequent access to NAND memory only affects power consumption, the read operation of 'Read size' is performed periodically. Read data requires a buffer that is temporarily stored until it is decoded in the audio codec. This is called a read buffer.

In the case where the data broadcast in the past has to be read at the request of the user, it can be done simply by changing the reading position to the past block.

<Resolves time loss when decoding stored data>
FIG. 7A is a diagram illustrating a problem that occurs when decoding erroneous data in a digital audio broadcasting data management method using a NAND flash memory according to an embodiment of the present invention.

Since data is transmitted over the airwaves, the DAB has a period of about 24 msec, as in Case 1 of FIG. 7A. When "MP2 B" and "MP2 C" are broken data due to uneven propagation, the data of the airwaves comes in at a certain time, so after decoding the "MP2 A", it waits for the next data "MP2 B" to arrive.
In the end, decoding failure occurs because of broken data. Even when the data is broken according to the real time of the broadcast data, processing of the broken data in accordance with the next synchronization can prevent the sound from getting faster because the total time of the speech sound and the music sound is correct.
However, the situation is different when reading and decoding buffered DAB data. When one piece of data ("MP2 A") is obtained and decoded, a time of 24 msec is obtained, and the next data is decoded within 24 msec. However, if the data is broken, the time value is different from On Air because it decodes the next data immediately. The sound accelerates with noise. To solve this problem, it is necessary to adjust the time period even for the broken data.

Therefore, the digital audio broadcast data stored in the circular ring buffer is decoded and reproduced at regular time intervals regardless of data errors, and the process is shown in FIG. 7B.

FIG. 7B is a diagram illustrating that a problem occurring when decoding an error data in a method of managing digital audio broadcasting data using a NAND flash memory according to an embodiment of the present invention is solved through a forced time interval cleanup.

As shown, even if the stored data is defective, time bundles are maintained by forcibly sending bundled data to the codec for time progression such as "On Air".

In addition, the DAB terminal includes an audio decoder and a read buffer, and the digital audio broadcast data stored in the circular ring buffer is first stored in the read buffer and then decoded and reproduced through the audio decoder, and the read buffer has to be read by manipulation of the key input unit. The reproduction position of the digital audio broadcast data is selected by varying the read position on the circular ring buffer.
Referring to FIG. 6, the audio decoder may be referred to as a simple operation of reading data from a read buffer and performing decoding. For example, when accessing past data and accessing some future data during past data access, only the read buffer needs to be moved by the read buffer according to the time value to be moved. Therefore, due to this technical configuration, the DAB data can be stored for more than one hour using a high capacity NAND memory to implement functions such as forwarding, rewinding and random access of the audio device.

Although the present invention has been described in more detail with reference to several embodiments, the present invention is not necessarily limited to these embodiments, and various modifications can be made without departing from the spirit of the present invention.

As described above, according to the digital audio broadcasting data management method using the NAND flash memory according to the present invention, since the hidden area of the NAND memory is inaccessible to the general user, the stored DAB audio data is copied to another device. Because you can't do this, you have the effect of keeping your data safe.

In addition, a high-capacity NAND memory can store audio data of several hours. Accordingly, a rewinding function or a fast-forwarding function can be conveniently implemented like a search of an audio device.

In addition, it is possible to access the random area of the stored data by using the “Moving buffer” and the block characteristics of NAND. When the broadcast condition is good, there is almost no loss of data of the airwaves. Since the correction is made to have the same time condition as, there is no effect of speeding up the sound.

Claims (6)

delete delete A broadcast receiving unit receiving a digital audio broadcast signal from a DAB radio station; Extracting digital audio broadcast data from the received digital audio broadcast signal; Setting up a circular ring buffer of a block unit data structure in a NAND memory; Setting a recording start position of the circular ring buffer according to a block boundary of the circular ring buffer; Setting a recording buffer having a multiple size of the block conversion prevention recording unit for recording data in the circular ring buffer; Storing the extracted digital audio broadcast data in the recording buffer; Extracting digital audio broadcast data from the recording buffer and sequentially recording the block to which the recording start position of the circular ring buffer belongs in the block conversion prevention recording unit; Setting up a read buffer having a predetermined read size; Reading digital audio broadcast data stored in the circular ring buffer according to an operation of a key input unit and storing the digital audio broadcast data in the read buffer; And Obtaining digital audio broadcast data from the read buffer and performing decoding reproduction; Digital audio broadcast data management method using a NAND flash memory comprising a. The method of claim 3, wherein Performing the decoding playback, Setting a forced time interval for the read buffer; Acquiring a decoding block of digital audio broadcast data from the read buffer at the set forced time interval regardless of whether there is an error of the digital audio broadcast data; And Decoding and reproducing digital audio broadcast data of the obtained decoding block; Digital audio broadcasting data management method using a NAND flash memory, characterized in that comprises a. The method of claim 4, wherein Providing an audio decoder and a read buffer; Digital audio broadcast data stored in the circular ring buffer is first stored in the read buffer and then decoded and reproduced through the audio decoder; Changing a read position on the circular ring buffer to be read by the read buffer by an operation of a key input unit; And Selecting a reproduction position of the digital audio broadcast data according to the read position variation; Digital audio broadcasting data management method using a NAND flash memory, characterized in that it further comprises. The method according to any one of claims 3 to 5, Setting the circular ring buffer, Providing a buffer space in a hidden area of the NAND memory; And Setting a circular ring buffer of a block unit data structure in the prepared buffer space; Digital audio broadcasting data management method using a NAND flash memory, characterized in that comprises a.

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