JPH01100644A - Memory control system - Google Patents

Abstract

PURPOSE:To widely reduce the capacity of a storage device by erasing storage contents before the writing of a signal in a writing period, erasing the storage contents after the reading of the signal in a reading period and shortening an action process. CONSTITUTION:A change-over switch 16 switches signals A and B by a signal C to show whether the action condition of a recording/reproducing device 15 is a recording or a reproducing and leads them out to an erasing circuit 12. At the time of the recording action of the device 15, the signal A is inputted to the circuit 12, the circuit 12 starts an erasing action in accordance with this signal A. On the other hand, the signal recorded in a recording medium 7 is read out by a magnetic head 6 and given to a demodulating circuit 9 through an amplifying circuit 8. The signal demodulated by this circuit 9 is stored into a device 2 and the correction of an error or the interpolation of the signal is executed in accordance with an correction signal added by an error correcting circuit 10. The signal to which a processing like this is executed is converted into an analog signal by a D/A converter and reproduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a recording/reproducing apparatus in which digital signals are recorded/reproduced on a recording medium via a storage device, that is, a pulse code such as a so-called digital audio tape (DAT). The present invention relates to a storage device control method suitably implemented in a storage device used in a modulation (PCM) signal recording/reproducing device, a compact disc reproducing device, and the like.

BACKGROUND ART Conventionally, when data is not temporally compressed in, for example, a PCM signal recording/reproducing device, a digital signal recorded on a recording medium such as a magnetic tape is read out by a magnetic head, as described below. The signals are stored in storage devices such as four memories, and subjected to signal processing. The signals sequentially output from the four storage devices are converted into analog signals and audible by a speaker.

Normally, when recording on a recording medium, the order of digital signals is temporally dispersed, that is, the arrangement position is changed by a method called increment. Therefore, during playback, the array must be restored to its original state. For this purpose, it is necessary to store the signals until interleaving is completed in a storage device.

Furthermore, storage devices cannot perform input and output simultaneously, so when continuous signal input/output such as audio output is required, several storage devices are switched and used in turn, and only one storage device is used. Operate so that a signal is always input or output from.

FIGS. 4 and 5 are diagrams for explaining a typical control method conventionally used in a storage device of a recording/reproducing apparatus. FIG. 4 shows the operation of the storage device during the recording operation of the recording/reproducing apparatus, and will be described below with reference to the same figure.

The storage device is an analog/digital converter (hereinafter referred to as A/D
Input of digital signals from converters (abbreviated as converters) (writing operation), signal processing such as adding correction codes (correction code addition operations), signal output for recording on recording media (continuous operation), and storage devices Erasing the memory contents (initialization operation)
The operation is divided into four steps.

Therefore, four memory devices MRI to MR4 are required to continuously write the signals from the A/D converters.

In the storage device MRI-MR4, the operations shown in FIGS. 4(1) to 4(4) are performed. For example, in a storage device MRI, an initialization operation is performed during a period TA, and an initialization operation is performed during a period TB.

A write operation, a correction code adding operation, and a read operation are respectively performed on the TC and TD, and these operations are repeated.

In the storage device MR2, a write operation, a correction code addition operation, a read operation, and an initialization operation are performed during periods TA, TB, TC, and TD, and these operations are repeated. That is, the storage device MR2 performs the same operation as the storage device MRI in advance for a predetermined period.

The storage device MR3 performs a similar operation for a certain period of time prior to the operation of the storage device MR2. Furthermore, the storage device MR4 performs a similar operation for a certain period of time prior to the operation of the storage device MR3. That is, during the same period, the storage devices MRI to MR4 operate differently. Therefore, in each period, a write operation is performed in one of the storage devices, and a read operation is performed in one storage device different from this storage device. In this way, write and read operations are performed continuously.

FIG. 5 shows the operation of the storage device during the reproducing operation of the recording/reproducing apparatus described above, and will be described below with reference to the same figure.

In the reproduction operation, the storage devices MRI to MR4 undergo four steps: erasing the stored contents (initialization operation), inputting from the recording medium (writing operation), and error correction of the written signal according to the added error correction code. signal processing such as correction (correction operation) and digital/analog converter (hereinafter referred to as D/A
(abbreviated as a converter), etc. (read operation).

Each memory device performs similar operations at predetermined intervals so that writing and reading from the memory devices MR1 to MR4 are performed continuously.

For example, in the storage device MRI, an initialization operation is performed during the period TAI, and a write operation, a correction operation, and a read operation are performed during the periods TBI, TCI, and TD1, and these operations are repeated.

Since the storage device MR2 performs a similar operation a certain period of time ahead of the storage device MHI, a write operation is performed during the period TAI. In this way, for example, during the period TAI, a write operation is performed in the memory device MR,2, and the memory device M
A read operation is performed in R4. During the period TB1, a write operation and a read operation are performed in the memory devices MR1 and MR3, respectively. In this way, memory bag g
Writing and reading are performed alternately in MR1 to MR4, allowing continuous writing and reading.

Problems to be Solved by the Invention In recent years, storage devices such as random access memory (RAM) have become cheaper. However, with the advancement of digital technology, for example, methods called 2x or 4x oversampling are used in sound reproduction equipment to improve sound quality, and storage devices are required to have large capacity and high-speed response. This is becoming more and more common.

Storage devices that meet these demands are generally expensive;
This results in an increase in the cost of the entire device.

Therefore, there has been a strong demand for a control system that can reduce the number of storage devices without impairing the performance of the entire device.

SUMMARY OF THE INVENTION An object of the present invention is to provide a storage device control method that solves the above-mentioned problems, allows a significant reduction in the capacity of a storage device without degrading performance, and requires almost no additional circuitry for this purpose. It is.

Means for Solving the Problems The present invention includes: a storage device into which digital signals are written and read; and addressing means for outputting an address at which the storage contents of the storage device are to be erased; During a write operation to the device, an address to be written is specified by an addressing means to sequentially erase the memory contents prior to the write operation, and during a read operation from the storage device, an address from which the memory contents were read is specified as an address. A control method for a storage device, characterized in that the storage contents are sequentially erased by designating means, and at least one of the storage contents erasing operations is selected during a write operation or a read operation. It is.

According to the present invention, the erasing operation of the memory contents prior to the write operation performed to the address specified by the address specifying means during the write operation of the memory device l\, and the address specifying means during the read operation from the memory device At least one of the read operation performed on the address designated by and the erase operation of the stored contents performed with a delay is selected and performed. Therefore, erasing of the memory device can be performed simultaneously during a writing or reading operation in a memory device that writes or reads a large capacity signal, thereby shortening the operation process of the memory device.

Embodiment FIG. 1 is a block diagram showing the configuration of a recording/reproducing apparatus 15 which is an embodiment of the present invention. The recording/reproducing device W 15 includes an erasing circuit 12 serving as an address specifying means, a storage device 2, and a changeover switch 16.

This recording/reproducing device 15 converts an analog signal into a digital signal, stores it in the storage device 2, performs signal processing to be described later, and records it on a recording medium 7 such as a magnetic tape. Further, the signal recorded on the recording medium 7 is read out and stored in the storage device 2,
The signal is processed to be described later to convert it into an analog signal and reproduce it.

For example, an analog signal such as an acoustic signal is sent to the A/D converter 1.
is converted into a digital signal by This digital signal is stored in a device consisting of three storage devices 2a, 2b, and 2C.The digital signal is processed by a correction code adding circuit 3, which adds a correction code to perform error correction called parity or signal interpolation. is added. Thereafter, the stored signal is outputted to the modulation circuit 4 and modulated, applied to the magnetic head 6 via the drive circuit 5, and recorded on the recording medium 7.

The changeover switch 16 switches the signals A and B in accordance with the signal C indicating whether the operating state of the recording/reproducing device 15 is a reproducing operation or a recording operation, and outputs the signals A and B to the erasing circuit 12. For example, during a recording operation of the recording/reproducing device 15, a signal A is input to the erasing circuit 12, and the erasing circuit 12 starts an erasing operation in accordance with this signal A.

The signal recorded on the recording medium 7 is read by the magnetic head 6 and is applied to the demodulation circuit 9 via the amplifier circuit 8.

The signal demodulated by the demodulation circuit 9 is stored in the storage device 2, and error correction or signal interpolation is performed according to the correction code added by the error correction circuit 10.

The signal subjected to such processing is converted into an analog signal by the D/A converter 11 and reproduced. During the reproducing operation, the changeover switch 16 outputs the signal B to the erasing circuit 12, and the erasing circuit 12 starts the erasing operation in accordance with the signal B.

FIG. 2 is a diagram showing the operation of the storage device 2 during recording operation, and FIGS. 2(1) to 2(3) show the storage device 2a,
The operations of 2b and 2c are shown respectively.

The three storage devices 2a, 2b, and 2c perform different operations in each period, such as writing, that is, inputting the signal from the A/D converter 1, and reading, that is, inputting the stored signal to the modulation circuit 4 and the drive circuit 5. The storage device 2 is controlled so that the operations of outputting the signal to the magnetic head 6 through the magnetic head 6 and recording on the recording medium 7 are performed continuously in the storage device 2 .

For example, in the memory bag fit 2 a, a write operation is performed during period T1, and a correction code addition operation is performed during period T5. Thereafter, a read operation is performed in a period T4 after a margin period TMI has elapsed.

At this time, the initialization operation is performed in a period T3 that starts slightly after the period T4. This initialization operation is led out to the erasing circuit 12 via the changeover switch 16, and is performed as shown in FIG.
It starts at the rising edge of signal A shown in 4). The erase circuit 12 sequentially specifies and erases the addresses of signals that have been read out, thereby performing so-called initialization.

Although it is necessary to erase the memory contents even after the read operation ends, there is a margin period TM2 after the read operation period T4, and the initialization operation ends before the next write operation is performed, that is, within this margin period TM2. In order to
No substantial time delay occurs.

The storage devices 2t+ and 2c are also the same as the storage device 2a described above.
Similar operations are performed at regular intervals. Therefore, for example, during period T1, a write operation is performed in the storage device 2.
The process is performed for the storage device 2C during the period T2, and is performed for the storage device 2b during the period T3, and such operations are repeated. Similarly, read operations are performed alternately in the storage devices 2a to 2C, and are performed continuously as a whole.

FIG. 3 is a diagram showing the operation of the storage device 2 during playback operation, and FIG. 3(1) to FIG.
The operations of b and 2c are shown respectively.

=11- Similar to the recording operation, the three storage devices 2a, 2b, and 2c perform different operations in each period, such as writing,
That is, the operation of inputting a signal from the recording medium via the magnetic head 6, the amplifier circuit 8, and the demodulation circuit 7 and the operation of reading, that is, outputting the stored signal to the D/A converter 11 are performed by the storage device 2. It is controlled so that it is performed continuously.

For example, in the storage device 2a, after the read operation is completed, at the rising edge of the signal B shown in FIG. The initialization operation is performed for T11. At this time, a write operation is performed in a period T14 that starts after a margin period TM3 after the start of the period T11.

The initialization operation is completed before the end of the write operation, and after the end of the write operation, waits for the elapse of the margin period TM4 and then starts the period T1.
In step 5, a correction operation is performed, that is, error correction or interpolation of the signal is performed according to the correction code added to the stored signal. After this, in period T13, output to the D/A converter 11, that is, a read operation is performed, and such an operation is repeated.

For the storage devices 2b and 2c, the same operation as that for the storage device 2a described above is performed with a certain period of time being shifted. Therefore, for example, in period Tll, the read operation is performed by memory bag W2.
c, and in period T12, storage device 2b
This is performed for the storage device 2a during period T13, and such operations are repeated. Similarly, write operations are performed alternately in the storage devices 2a to 2C, and are performed continuously as a whole.

In this way, the input/output of the storage device 2 in the recording/reproducing device 15 is performed continuously, and even in the case of, for example, an audio signal, recording/reproducing is performed without interruption. Conventionally, in order to realize such a function, a storage device with a storage capacity four times the storage capacity for storing signals until one period of interleaving is completed was required, but in this embodiment, The storage capacity can be reduced to 3/4 of the conventional size, and only a small amount of additional circuitry is required to achieve this.

Although this embodiment shows a case where the signal is not temporally compressed as is done in digital audio technology, the present invention can also be implemented when the signal is temporally compressed. Further, during the recording operation of the recording/reproducing device 15, the erase operation of the stored contents during the read operation was selected, but the erase operation of the stored contents during the write operation may also be selected. Further, in the reproduction operation, the erase operation of the stored contents during the write operation is selected, but the erase operation of the stored contents during the read operation may be selected.

Effects As explained above, according to the present invention, the memory contents are erased prior to the writing of the signal during the period of writing to the storage device, or are erased following the reading of the signal during the period of reading from the storage device. The memory contents will be erased. Therefore, the writing or reading operation of the storage device can be performed during the same period as the erasing of the storage contents. Therefore, the operating process is shortened, and the capacity of a storage device in a recording/reproducing device or the like can be significantly reduced, and costs can be reduced without impairing the performance of the device.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a recording/playback device 15 which is an embodiment of the present invention, FIG. 2 is a diagram showing the operation of the storage device 2 during the recording operation of the recording/playback device 15, and FIG. 4 is a diagram showing the operation of the storage device 2 during the reproducing operation of the recording/reproducing apparatus 15, FIG. is the storage device MRI during the playback operation of the prior art recording/playback device~
It is a figure which shows the operation|movement of MR4. 2...-Storage device, 3... Correction code addition circuit, 6...
・Magnetic head, 7... Recording medium, 10... Error correction circuit, 12... Erasing circuit, 15... Recording/reproducing device, 16... Changeover switch agent Patent attorney Number of strokes Keibu 1st Figure 20

Claims (1)

[Scope of Claims] A storage device into which digital signals are written and read, and an address specifying means for outputting an address at which the storage contents of the storage device are erased, and when a write operation is performed on the storage device. Prior to a write operation, the memory contents are sequentially erased by specifying the address to be written by the address specifying means, and when reading from the storage device, the address from which the memory contents were read is specified by the address specifying means. 1. A control method for a storage device, characterized in that the storage contents are sequentially erased using the following steps, and at least one of the storage contents erasing operation is selected during a write operation or a read operation.