JP2000260116A - Cd signal processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lighten the load of processing and to obtain economical simple constitution by allowing a CPU to receive specific data update information, directly take only necessary subcoding Q data out of a buffer part, and perform the process. SOLUTION: A CPU 14 once receiving the data update information of a subcoding Q data frame recognizes it, supplies the necessary address of subcoding Q data to an address decoding 15 from the updated subcoding Q data frame through an address bus 16, and supplies the decoded address to a subcoding Q data buffer part 13. Then the obtained subcoding Q data is used to read a necessary data part from a RAM, and the data part is processed as needed to perform various processes complying with a current request such as the reproduction of a movement corresponding to a program command, a display of the elapsed time in the movement, or a display of the absolute time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a CD signal processing apparatus for processing sub-coding in a CD signal, in particular, Q-channel sub-coding.

[0002]

2. Description of the Related Art On a CD (compact disk), in addition to a frame synchronization signal and a digital audio signal, one symbol consisting of 8 bits called a subcode is recorded for each frame. Then, as sub-coding, 98 such frames constitute 1
One block, ie, a sub-coding frame.

[0003] In this subcoding, if an 8-bit code is P, Q, R, S, T, U, V, W, P, Q
Are used to provide a program start function and a program start function, and R to W are used to provide special functions such as a still image and karaoke character display.

The CD signal processing apparatus uses the Q channel data during subcoding to reproduce a movement according to a program command, display an elapsed time in the movement, or display an absolute time. Such as
Various processes are performed according to the request at that time. In addition,
P channel data during subcoding has only a function for rough cueing and can be substituted with Q channel data.
The R to W channel data is for a special function and is not often used.

FIG. 3 is a diagram showing a configuration of a conventional CD signal processing apparatus which performs various processes using Q channel data during subcoding. Note that, in FIG.
Only items related to the processing of Q channel data during subcoding among the signal processing devices are described.

In FIG. 3, a CD signal processing unit 21 includes a subcoding Q data generation unit 22 and a subcoding Q data generation unit 22.
It has a data buffer unit 23, an interface unit 24, and a data update signal line 25.

[0007] The sub-coding Q data generation unit 22
The Q channel data under subcoding is extracted from the read CD data to generate a subcoding Q data frame, which is output to the subcoding Q data buffer unit 23, and a data update signal line 25.
Output the update information of the Q data.

[0008] Sub-coding Q data buffer unit 23
Stores the new subcoding Q data frame from the subcoding Q data generation unit 22,
The sub-coding Q data frame stored through the interface unit 24 is output to the microprocessor unit 31 in response to the request signal.

The microprocessor unit 31 includes a CPU (central processing unit) 32, a RAM (random access memory) 33, an interface unit 34, and an address bus 35.
And a data bus 36.

When the CPU 32 receives the update information of the Q data via the data update signal line 25, the CPU 32 generates a request signal in accordance with the progress of its own program, and outputs the updated subcoding data from the subcoding Q data buffer unit 23. Read the Q data frame. The read sub-coding Q data frame is transmitted to the interface unit 2
4. The data is updated and written in a predetermined address of the RAM 33, that is, a workspace for the sub-coding Q data, instructed by the CPU 32 via the interface unit 34 and the data bus 36, instead of the previous data.

From the sub-coding Q data written in the RAM 33, predetermined data in the sub-coding Q data is read out in accordance with a process to be executed based on a command from the CPU 32.

The signal processing of the conventional CD signal processing device comprising the CD signal processing section 21 and the microprocessor section 31 is performed as follows. That is, the sub-coding Q data frame is composed of a movement number TNO, an index X, an elapsed time (minute, second, frame number) in the movement,
It is composed of data parts such as absolute time (minutes, seconds, frame numbers) and the like, which are stored in the subcoding Q data workspace of the RAM 33.

The necessary data portion of the sub-coding Q data is read from the RAM 33 in accordance with the processing requested at that time, and the necessary processing is performed, thereby reproducing the movement according to the program command. For example, the elapsed time in a movement is displayed, or the absolute time is displayed, and various processes are performed according to the request at that time.

Here, the processing flow of the CPU 32 when performing the skipping check process using the sub-coding Q data will be described with reference to FIG.

First, in step S21, the CPU 32 receives data update information from the data update signal line 25. In step S22, the CPU 32 sends a subcoding Q data frame read request signal to the subcoding Q data buffer unit 23. In step S23, each data of the sub-coding Q data frame is read from the sub-coding Q data buffer unit 23, and all the data are sequentially stored in the RAM 33 according to the address given to the address bus 35.

In step S24, the total minute, second, frame number, that is, the absolute time, which is data necessary for the skip check, is read. In step S25, the presence / absence of sound skip is checked from the newly read total minute, second, and frame number and the previous total minute, second, and frame number stored in the CPU. Take action according to the results. Then, in step S26, the sound skip check ends.

As can be seen from this specific example, in order to perform some processing, the latest subcoding Q data is always required. Even if the sub-coding Q data used for this processing is a part of data, the entire sub-coding Q data frame generated by the sub-coding Q data generation unit 22 at regular intervals (about 13.3 ms) is In accordance with the data update information from the data update signal line 25, the data is taken into the RAM 33 via the sub-coding Q data buffer unit 23, the interface unit 24, the interface unit 34, and the data bus 36. Then, it is configured to store a new subcoding Q data frame in place of the previous data.

[0018]

In the conventional CD signal processing apparatus, the processing according to the request at that time can be performed using the sub-coding Q data. However, although only a part of the sub-coding Q data is used, the microprocessor unit 31 needs to perform a process of taking in the sub-coding Q data frame at regular intervals. As a result, it is necessary to prepare a CPU 32 having higher capability.

Further, in order to provide an interface between the CD signal processing section 21 and the microprocessor section 31, both the interface section 24 and the interface section 34 are required, and it is necessary to provide a work space for subcoding Q data in the RAM 33. Therefore, the size of the CD signal processing device becomes large, and the CPU 32
And it was expensive.

Therefore, according to the present invention, the C signal processing unit and the microprocessor unit are divided into two parts.
The D signal processing device is integrated into one chip to simplify the configuration, and the CPU is configured to process only a necessary data portion of the sub-coding Q data frame, thereby reducing the processing load and economically. Simple configuration C
It is intended to be a D signal processing device.

[0021]

A CD signal processing apparatus according to claim 1 extracts a subcoding Q code from a signal read from a CD, generates and outputs a subcoding Q data frame, and outputs the subcoding Q data frame. Sub-coding Q data generating unit for outputting the fact that has been generated as data update information, and sub-coding for receiving a sub-coding Q data frame from the sub-coding Q data generating unit and storing the sub-coding Q data in a readable manner for each sub coding Q data A Q data buffer unit, a CPU, and an address decoder for converting a read address from the CPU into each subcoding Q data address of the subcoding Q data buffer unit, wherein the CPU receives the data update information. Is needed Read directly only subcoding Q data from said buffer unit, and performs processing.

According to this configuration, the sub-coding Q data buffer section is allocated on the memory map on the microprocessor section side, and each sub-coding Q data is individually directly transmitted from the CPU as needed. Since it is configured to be readable, the sub-coding Q data buffer functions as a buffer as in the related art when viewed from the CD signal processing unit, and the sub-coding Q data buffer when viewed from the microprocessor. Section functions as work memory, so C
The D signal processing device can be used in the same manner as the conventional one.

Since it is not necessary to read the sub-coding Q data frame into the work memory on the microprocessor side and then process the sub-coding Q data frame, it is possible to save time for loading the sub-coding Q data frame and to secure a work memory. Disappears. Further, since only necessary data can be directly read, the processing time can be reduced, and it is not necessary to use a CPU having higher capability.

Further, the interface between the CD signal processing section and the microprocessor section can be simplified, and there is no need to provide a separate work space for sub-coding Q data. Can be.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described.
This will be described with reference to FIGS. FIG. 1 is a diagram showing a one-chip CD signal processing apparatus according to an embodiment of the present invention, in which only matters relating to processing of Q channel data during subcoding, which is a feature of the present invention, are described.

In FIG. 1, the CD signal processing device 11
The sub-coding Q data generation unit 12 and the sub-coding Q data buffer unit 1 are formed on a chip.
3, a CPU 14, an address decoder 15, an address bus 16, a data bus 17, and a data update signal line 18. The left side of the broken line in the center of FIG. 1 corresponds to the conventional CD signal processing unit, and the right side thereof corresponds to the conventional microprocessor unit. As a result, the subcoding Q data buffer unit 13 functions as a RAM. Is also functioning, indicating that they are shared from both sides.

The sub-coding Q data generation unit 12
The Q channel data under subcoding is extracted from the read CD data, a subcoding Q data frame is generated at regular intervals (about 13,3 ms), and this is output to the subcoding Q data buffer unit 13. At the same time, Q data update information is output by the data update signal line 18.

Sub-coding Q data buffer section 13
Receives a new subcoding Q data frame supplied at regular intervals (approximately 13,3 ms) from the subcoding Q data generation unit 12 and stores it at a predetermined address so as to be readable for each subcoding Q data. The sub-coding Q data is output according to the read address signal.

When receiving the update information of the Q data via the data update signal line 18, the CPU 14 recognizes that the subcoding Q data frame has been updated to new data. And, as your program progresses,
Obtain only the required subcoding Q data from the updated subcoding Q data frame.

In this case, the address of the required sub-coding Q data is output from the CPU 14, and this address is decoded by the address decoder 15, and the sub-coding Q data in which the actually required sub-coding Q data is stored. The address of the data buffer unit 13 is issued, and the data is read. The reading of the sub-coding Q data is to arbitrarily read only the necessary sub-coding Q data at a necessary time according to an instruction from the CPU 14 in accordance with the processing performed as the CD signal processing device.

As can be seen from the storing and reading operations, the sub-coding Q data buffer 13
When viewed from the signal processing unit side, it functions as a buffer as in the past, whereas when viewed from the microprocessor unit side, only necessary subcoding Q data is arbitrarily read at the required time, It functions as a work memory similar to a conventional RAM.

In this embodiment, the address decoder 15 for converting the address of the subcoding Q data output from the CPU 14 to the address of the subcoding Q data buffer unit 13 is provided.
If the configuration is such that the address output from U14 is output in the form of the address of the actual subcoding Q data buffer unit 13, the address decoder 1
5 need not be provided.

The signal processing of the CD signal processing device 11 according to the embodiment of the present invention is performed as follows.

The sub-coding Q data frame generated by the sub-coding Q data generating unit 12 at regular intervals (about 13,3 ms) is output to the sub-coding Q data buffer unit 13 every time it is generated. Each coding Q data is stored at a predetermined address so as to be readable. At the same time, the data update information of the sub-coding Q data frame is
8 to the CPU 14.

The CPU 14 performs the processing according to the program. When it receives the data update information of the sub-coding Q data frame, it recognizes this. Then, as the processing proceeds, the updated subcoding Q
The required address of the subcoding Q data from the data frame is supplied to the address decoder 15 via the address bus 16, and the decoded address is supplied to the subcoding Q data buffer unit 13. As a result, only the designated subcoding Q data in the updated subcoding Q data frame is obtained from the subcoding Q data buffer unit 13.

Using the obtained sub-coding Q data, the necessary data portion of the sub-coding Q data is read out from the RAM 33 in accordance with the process requested at that time, as described above, and Various processes are performed according to the request at that time, such as playing the movement according to the program command, displaying the elapsed time in the movement, or displaying the absolute time. Will be

Here, in order to compare the embodiment of the present invention with the conventional one, the processing flow of the CPU 14 when performing the skipping check processing using the sub-coding Q data will be described with reference to FIG. explain.

First, in step S11, the CPU 14 receives data update information from the data update signal line 18. In step S12, the total minute, second, frame number, that is, the absolute time, which is the data necessary for the skip check, is read. In step S13, the presence / absence of a skip is checked from the newly read total minute, second, and frame number and the previous total minute, second, and frame number held in the CPU. Take action according to the results. Then, in step S14, the sound skip check ends.

As can be seen from this specific example, in order to perform some processing, the latest sub-coding Q data is always required. In the embodiment of the present invention, however, the sub-coding Q data is provided at regular intervals (about 13.3 ms). Without taking the entire subcoding Q data frame generated by the subcoding Q data generation unit 12 into the microprocessor unit side,
For that particular process, use the subcoding Q
It is configured to capture only data when needed.

For this reason, the processing to be borne by the CPU 14 for the specific processing, in this example, the skipping check, is as follows.
Only the specific subcoding Q data to be used need be handled, which is significantly reduced as compared with the conventional CPU processing.

As described above, in the embodiment of the present invention, the CD of the sub-coding Q data
When viewed from the signal processing unit side, the sub-coding Q data buffer unit 13 functions as a buffer as in the related art, and when viewed from the microprocessor unit such as the CPU 14, the sub-coding Q data buffer unit 13 functions as a work memory. Therefore, the present invention can be used as a conventional CD signal processing device.

In particular, in the processing using the subcoding Q data, attention is paid to the fact that only a part of the subcoding Q data is used.
Since the data buffer unit 13 is configured to be used both as a component on the CD signal processing unit side and as a component on the microprocessor unit side, the sub-coding Q data frame is read into the work memory on the microprocessor unit side. , There is no need to perform any processing, and the time to capture the subcoding Q data frame can be saved, and it is not necessary to secure a work memory. In addition, since only necessary data can be directly read, the processing time can be reduced, and it is not necessary to use a CPU 14 having higher performance.

[0043]

According to the structure of the first aspect, the sub-coding Q data buffer section is allocated on the memory map of the microprocessor section side, and each sub-coding Q data is individually transmitted from the CPU as needed. When viewed from the CD signal processing unit side, the sub-coding Q data buffer unit functions as a buffer as in the prior art, and conversely, when viewed from the microprocessor unit side, the sub-coding Q data buffer unit functions as a buffer. Since the data buffer functions as work memory,
The CD signal processing device can be used in the same manner as a conventional one.

Further, since it is not necessary to read the sub-coding Q data frame into the work memory on the side of the microprocessor and then to process the data frame, the sub-coding Q data frame is not necessary.
The time to capture the data frame can be saved, and there is no need to secure a work memory. Further, since only necessary data can be directly read, the processing time can be reduced, and it is not necessary to use a CPU having higher capability.

Further, the interface between the CD signal processing section and the microprocessor section can be simplified, and there is no need to provide a separate work space for sub-coding Q data. Can be.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a CD signal processing device using Q channel data according to an embodiment of the present invention.

FIG. 2 is a flowchart in the case of performing a skipping check process according to the embodiment of the present invention.

FIG. 3 is a diagram showing a configuration of a conventional CD signal processing device using Q channel data.

FIG. 4 is a flowchart in the case of performing a conventional skipping check process.

[Explanation of symbols]

 Reference Signs List 11 CD signal processing device 12 Subcoding Q data generation unit 13 Subcoding Q data buffer unit 14 CPU 15 Address decoder 18 Data update signal line

Claims (1)

[Claims] 1. A sub-coding for extracting a sub-coding Q code from a signal read from a CD to generate and output a sub-coding Q data frame, and for outputting the generation of the sub-coding Q data frame as data update information. A Q data generation unit; a subcoding Q data buffer unit that receives a subcoding Q data frame from the subcoding Q data generation unit and stores the subcoding Q data frame in a readable manner for each subcoding Q data; An address decoder for converting an address into each sub-coding Q data address of the sub-coding Q data buffer unit, wherein the CPU receives the data update information and stores only the necessary sub-coding Q data in the buffer. Read directly from the part, CD signal processing apparatus and performs processing.