JPS62182919A - Data transfer controller - Google Patents

Abstract

PURPOSE:To minimize the time related to a data compressor and to improve the use efficiency of a computer by comparing the compression processing time of remaining data with the time of transfer of all stored compressed data to the computer and starting data transfer to the computer from the second memory when both times coincide with each other. CONSTITUTION:A subtractor 13 subtracts a forecasted number N of times of access to a data compressor B during data transfer to a host computer A from a number N0 of times of access to the compressor B, which is required for compression processing of all data, to calculate Ns, and a comparator 14 compares the output of a counter 8 with Ns, and the transfer of compressed data is started when they are equal to each other. When the counted value of the counter 8 reaches Ns, the transfer for compressed data from an output buffer 3 to the computer A is started. The compression processing of remaining data is performed in parallel with the transfer of compressed data to the host computer A, and the compression processing of remaining data is terminated simultaneously with the end of transfer of data.

Description

[Detailed description of the invention] [J! Required: A data transfer control device that controls data transfer between a computer and a data compression device, and which finishes compression processing of remaining uncompressed data while transferring compressed data after processing to the computer. By optimizing the timing of data transfer in this way, the time the computer spends on the data compression device is minimized, thereby improving the efficiency of computer usage.

[Industrial application field]

The present invention relates to a data transfer control device, and more particularly to a device for controlling data transfer between a computer and a data compression device.

When a computer transfers data between other computers, the time required for data transfer should be as short as possible.The longer the time involved in data transfer, the less time the computer has to perform its normal operations. This is because the efficiency of using the computer decreases. In particular, when transferring image data, since the amount of data is large, it takes a long time to transfer, which has been a problem in the past.

Therefore, when transferring such image data, the transfer time is reduced by compressing the data and reducing the amount of data to be transferred.

[Conventional technology]

FIG. 3 is a block diagram illustrating conventional data transfer. C is a scanner, which transfers the collected image data to host computer A. B is a data compression device, which compresses the data transferred from the host computer A and then transfers it to the host computer A. D is an output computer that receives compressed image data transferred from the host computer, and F is a data restoration device that restores the compressed image data transferred from the output computer D to the original data. E is a plotter, which plots the restored data transferred from the output computer.

By reducing the amount of data transferred by compressing the data in advance in this way, it becomes possible to significantly reduce the time required to transfer data from the host computer A to the output computer D.

However, since the host computer A needs to transfer data to and from the data compression device 21B for data compression, it is not possible to transfer data with other devices during this transfer time.

[Problem that the invention seeks to solve]

By the way, according to the conventional example, from the host computer A to the data compression device 2! When transferring image data to the IB, the amount of data corresponding to the processing capacity of the data compression unit 21B is transferred to the data compression unit 2tH, and when the compression process is completed, the compressed data is received and then transferred to the next division. The configuration is such that data is sent. That is, the host computer A has to transfer the image data in several batches and wait until all the compression processes are completed, which causes a problem in that the usage efficiency of the host computer decreases.

The present invention was created in view of the problems of the prior art, and aims to provide a data transfer control device that minimizes the time the computer spends on the data compression device and improves the efficiency of computer usage. do.

[Means for solving problems]

The present invention includes a first memory that temporarily stores uncompressed data transferred from a computer, a second memory that temporarily stores compressed data transferred from a data compression device,
means for dividing the data stored in the first memory according to the compression processing speed of the data compression device and transferring the divided data to the data compression device; and the first memory after being transferred to the data compression device. a first measurement stage that measures the amount of data remaining in the data, compressed by a data compression device;
a second measuring means for measuring the length of the compressed data transferred to the memory of 1; a third measurement-L stage for measuring a total of 1-L; a fourth measuring means for measuring the amount of data transferred from the computer to the first memory during the time measured by the third measuring means; For the first total AN means, (
(Determine the time to compress the remaining data based on the amount of remaining data and the processing time based on the third measuring means, and further calculate the time for compressing the remaining data and the amount of time stored in the second memory calculated by this time and the fourth measuring means.) The present invention is characterized by comprising means for comparing the time required to transfer all the compressed data to the computer, and when these times become equal, starting data transfer from the second memory to the computer.

[Effect]

All data transferred from the computer is first stored in the first memory. This allows the computer to be accessed by other devices.The transfer means transfers a predetermined amount of data according to the processing usage of the data compression device to the first
The data is transferred from the memory to the data compression device. At this time, the remaining data charges are measured one by one by the first measuring means.

Further, the third measuring means measures the time it takes for the data compression device to process a predetermined amount of data. At this time, the amount of data transferred from the computer to the first memory within this processing time is measured by the fourth total Am T'.

Compressed data compressed by the data compression device is transferred to the second memory. The total amount of data stored in the second memory is measured by the second measuring means.

Since the time required to compress a predetermined amount of data that has been compressed is known by the third measuring means, and the amount of remaining uncompressed data is known by the first measuring means, the remaining uncompressed data The time required for compression processing can be calculated.

Furthermore, the amount of data that can be transferred from the computer to the first memory within the time required to compress the divided predetermined amount of data can be determined by the fourth measuring means; This is considered to be approximately equal to the amount of data that can be transferred.

Therefore, when the time required to compress the uncompressed data remaining in the first memory is equal to the time required to transfer all the compressed data stored in the second memory to the computer, the compressed data is If you start transferring data to the computer, the compression process for uncompressed data will just stop when the transfer is finished. In this way, data transfer and compression processing can be performed in parallel.
It becomes possible to minimize the time involved in the computer's data compression equipment. Therefore, it is possible to improve the usage efficiency of the computer.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the configuration of a data transfer control device according to an embodiment of the present invention.

1 is an input/output section 1111, through which uncompressed data is transferred from the host computer A to the power buffer 2, and compressed data is transferred from the output buffer 3 to the host computer A. 2 is a manual buffer that temporarily stores data transferred from the host computer. 3 is the data pressure m''''A fi! via the device control unit 5. I
This is an output buffer that temporarily stores compressed data transferred from B.

4 is a counter that counts the amount of data transferred to the input buffer 2, and the counted amount is transferred to the data compression device B.
The data compression unit 21B controls the device control unit 5 by outputting a signal every time the processable data amount reaches
Ensure that the amount of data that exceeds the processing capacity is not transferred.

This amount of data is called the unit access processing data amount. 5 is a device control ffi through which data is transferred from the input buffer 2 to the data compression device B.

Data compression system f? Compressed data is transferred from iB to output buffer 3.

6 is data compression device 2! IB is unit access processing data
This is a counter that counts the amount of data L1 transferred from the host computer A to the input buffer 2 while compressing J. Here, what is the time taken by the data compression device to compress unit access processing data, %l?

This refers to the period from when the first data begins to be written from the input buffer 2 to the data compression device B via the device control unit 5 until the last data compressed by the data compression device 2iB is read out to the output buffer 3. 6 is device control 1 when the first data becomes old.
A counting operation is started by a signal outputted from the device controller 5, and is ended by a reset signal outputted from the device controller 5 when the last compressed data is read.

7 is data written from the input buffer 2 to the data compression device B via the device control unit 5? This is a counter that counts M (stitches of '11th position access processing data).

That is, the counter 7 starts counting by the set signal output from the device control section 5 when writing of the first data starts, and starts counting operation by the reset signal output from the device control J1 section 5 when the writing of the last data ends. Stop counting operation.

8 is a counter that counts the number of times the data compression device 21B is accessed, and the count increases by one each time unit access processing data is written to the data compression device B.
9 is a counter that counts the data amount m after the intermediate access processing data has been compressed by the compression device B.

IO is a comparator that compares the output M of the counter 7 and the output m of the counter 9 and calculates the ratio thereof.

This ratio α=m/M indicates the data compression rate.

11 is the total data transferred from the host computer
This is a comparator that calculates the expected total cost of compressed data by multiplying ¥L (informed in advance by the host computer before transfer) and the data compression rate α.

A comparator 12 calculates the number of times the data compression device B can access the unit access processing data amount within the time required to transfer the total amount of compressed data from the output buffer 3 to the host computer A. That is, since the data transfer speed from the host computer A to the input buffer 2 and the data transfer speed from the output buffer 3 to the host computer are almost the same, the output L1 of the counter 6 is transferred to the output buffer within the processing time of unit access processing data. This shows data 14 that can be transferred from 3 to host computer A. Therefore, the number of times N that the data compression device 1B can access while transferring the entire compressed data sentence to the host computer is calculated by N=Ki/Ll.

Reference numeral 13 denotes a differentiator, which is expected to access times 1 during data transfer from IFk No to host computer A for all access times when data compression device B must be accessed in order to compress all data. Subtract N and get Ns
Calculate.

14 is the output of counter 8 (actual number of accesses) and MS
When they become equal to 1, the input/output control unit l° is activated and the transfer of compressed data from the output buffer 3 to the host computer A is started.

That is, when the count of the counter 8 reaches NS, transfer of compressed data from the output buffer 3 to the computer A is started. The remaining data is compressed in parallel with the compressed data being transferred to the host computer A.

Furthermore, since the configuration is such that the compression processing of the remaining data is completed at the same time as the transfer is completed, it is possible to subsequently transfer these remaining compressed data. In this way, the time that the host computer A spends on the data compression device B can be significantly reduced, so that the efficiency of computer use can be improved.

FIG. 2 is a diagram illustrating the outline of the operation of the data transfer control device according to the embodiment of the present invention. In FIG. 0, tl indicates the time for all data to be transferred from host computer A to input buffer l.

t2 is the time for compression processing by the data compression device 21B, and the compression processing starts from the middle of tl.

When all data transfer to the input buffer 2 is completed, the computer A is released and can perform other tasks such as data transfer with other devices.

When the compressed data reaches a predetermined amount, transfer of the compressed data to computer A is started. At this time, some of the remaining data is still being compressed or is in an uncompressed state, but when the compressed data transfer is finished, the compression process for these data will also be finished, so the data will continue to be compressed. It becomes possible to transfer the data to computer A. This total transfer time is indicated by t4.

As described above, according to the fifth embodiment of the present invention, data transfer and compression processing can be performed concurrently. Therefore, the time t2 during which the computer is free can be increased, and the efficiency of use of the computer can be improved.

〔Effect of the invention〕

As explained above, according to the present invention, data transfer and compression processing can be performed in parallel, and even though the processing capacity of the data compression device is limited, the computer can transmit all data at once. Since compressed data can be received all at once, the time involved in the data compression device can be minimized and the efficiency of computer use can be improved.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a data transfer control device according to an embodiment of the present invention, and FIG. 2 is a diagram illustrating Mw8 of data transfer and operation of a TJJW device according to an embodiment of the present invention. FIG. 3 is a block diagram illustrating conventional data transfer. (Explanation of symbols) A...Host computer, B...Data compression device, C...Scanner. D...Output computer, E...Plotter. F...Data restoration device, l...Input control unit. 2... Large power buffer (first memory). 3... Output buffer (second memory), 4.6 to 10
···counter. 5...Device control unit, 11.12.14...Comparator, 13...Differentiator. Part 2 @J

Claims (1)

[Scope of Claims] A first memory that temporarily stores uncompressed data transferred from a computer; a second memory that temporarily stores compressed data transferred from a data compression device; means for dividing the data stored in the first memory according to the compression processing capacity and transferring the divided data to the data compression device; a first measuring means for measuring the amount of compressed data piece by piece; a second measuring means for measuring the amount of compressed data compressed by the data compression device and transferred to the second memory; a third measuring means for measuring the time required for the amount of data to be compressed by the data compression device; and data transferred from the computer to the first memory during the time measured by the third measuring means. a fourth measuring means for measuring the amount of data; and a time for compressing the remaining data based on the remaining data amount based on the first measuring means and a processing time based on the third measuring means, Compare the time required to transfer all the compressed data stored in the second memory to the computer calculated by the fourth measuring means, and when these times become equal, transfer the data from the second memory to the computer. A data transfer control device comprising means for starting data transfer.