JPH04349582A - Data input system - Google Patents

Abstract

PURPOSE:To directly input the data generated at a constant speed from an image reader, etc., to a host computer without providing an exclusive memory and a controller. CONSTITUTION:At the time of reading out data from an image reader 1, the data quantity to be read out is calculated, whether an area which can store its data quantity exists in a main memory 4 in a host computer 2 or not is decided, the data of an insufficient area portion is transferred and saved in an external disk memory 12 from the main memory 4, a data input from others to the area obtained thereby is locked, read-out data from the image reader 1 is inputted and after the data input is completed. the lock is released.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data input method for reading a predetermined amount of data at a constant speed, such as in an image reader device.

0002

2. Description of the Related Art FIG. 3 is a schematic diagram of a conventional image data input method. In the figure, 1 is an image reader device, 2 is a host computer, 3 is a central processing unit of this computer 2, 4 is its main memory, 5 is an image reader control device, 6 is its dedicated memory, and 7 is the image reader device. 1
8 is a data line from the image reader device 1, 9 is a signal line between the image reader control device 5 and the central processing unit 3, and 10 is a data line from the dedicated memory 6 to the main memory 6.

Next, the operation of the conventional data input method shown in FIG. 3 will be explained with reference to the flowchart shown in FIG. Now, when an input command is sent from the central processing unit 3 of the host computer 2 to the image reader control device 5, the image reader control device 5 starts the image reader device 1,
In step 41, the data to be read from now on is input, and in step 42, it is stored in the dedicated memory 6. Since the data reading section of the image reader device 1 operates mechanically, once the operation starts, it generates read data at a constant speed until the end of the operation. Therefore, the image reader control device 5 stores and holds the generated data in its own dedicated memory 6. .

When the input to the dedicated memory 6 is completed, a notification to that effect is sent from the image reader control device 5 to the central processing unit 3, and in step 43, an empty area is prepared in the main memory 4 to enable data input. The input request is sent to the image reader control device 5 and accordingly step 4
In step 4, the data in the dedicated memory 6 is sent to the host computer 2, and in step 45, the sent data is input into the main memory 4.

In this way, in the host computer 2, image data is input into the main memory 4 at an arbitrary timing, regardless of the reading speed determined by the mechanical characteristics of the image reader 1.

[0006]

[Problems to be Solved by the Invention] Since the data input method of the conventional image reader is as described above, image data inputted at a constant speed is temporarily stored in a dedicated memory, and then output requests from the host computer are processed. However, since the image data must be sent to the recipient, it is necessary to prepare a dedicated memory with a capacity that can store the maximum amount of image data, resulting in problems such as an increase in the size of the device and the inability to use the memory efficiently.

The present invention was made to solve the above-mentioned problems, and is capable of processing image data input at a constant speed without using a dedicated memory, and also allows the control to be performed by the central processing unit of the host computer. The purpose is to obtain a data input method that can be directly processed.

[0008]

[Means for Solving the Problems] The data input method according to the present invention includes a read data amount calculation means for calculating the amount of data to be read in response to the start of reading data, and a data amount calculated by the means for storing the data amount. main memory free space determining means for determining whether or not there is an area in the main memory with a size corresponding to The apparatus includes a data input means for inputting the read data into the main memory after the data is saved, and a memory lock means for locking data input from other sources during the read data input period.

[0009]

[Operation] In the data input method of this invention,
Calculate the amount of data to be read in response to the start of data reading, and if there is not enough free space in the main memory of the computer to store that amount of data, transfer the data for the insufficient space to external memory. This allows the data to be input directly into the main memory of the host computer, making more efficient memory use possible without the need for dedicated memory.

0010

[Embodiment] FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention. In the figure, 1 is an image reader device, 2 is a host computer, 3 is a central processing unit of this computer 2, and 4 is its main memory. , 7 is a signal line to the image reader device 1, 1
1 is a memory management unit of the computer 2, 12 is an external memory for saving data which is a disk memory, 13 is a data line from the image reader device 1 to the main memory 4, and 14 is a data line from the main memory 6 to the external memory. be

[0011]
Next, the operation of the embodiment of the present invention shown in FIG. 1 will be described with reference to the flowchart in FIG. Now, when the central processing unit 3 of the host computer 2 determines the input from the image reader device 1, in step 21, the central processing unit 3 determines the amount of data to be read based on the length and width of the image and the data density. Calculated (read data amount calculation means). Then, in step 22, it is determined whether the amount of read data can be input into the free area of the main memory 4 (
If input is not possible due to insufficient free space (main memory free space determination means), the process proceeds to step 23, and the memory management unit 11 saves data that can be saved in memory corresponding to the insufficient amount of data to an external memory for data saving. An empty area is created in the main memory 4 by moving the data to the memory 12 (data saving means). When a free space is created in the main memory 4, in step 24 the free space is locked to prevent input from others (memory locking means), and in step 25
Then, input processing of read data from the image reader 1 to that area of the main memory 4 is performed (data input means). When the input processing is completed, the main memory 4 is unlocked in step 26, and thereafter this area of the main memory 4 automatically becomes a data area equivalent to that of other programs, and can be moved to other processing as is.

[0012] In the above embodiment, a method of inputting read data from an image reader device has been described, but it is also possible to input data from a device that must obtain data in real time within a certain period of time, such as a paper tape reader device. is also applicable.

[0013]

As described above, according to the present invention, the amount of data to be read is calculated in response to the start of data reading, and there is no free space in the main memory of the computer large enough to store the calculated amount of data. At the time, the data for the insufficient area was transferred to external memory, so there was no need for an external control device for inputting data or a dedicated memory for inputting it, making the device inexpensive and allowing input data to be transferred to an external memory. Since the data is written directly to the main memory, the number of data transfers is reduced and the performance of the host computer is improved.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of this embodiment.

FIG. 3 is a schematic configuration diagram showing a conventional data input method.

FIG. 4 is a flowchart showing the operation of the data input method of FIG. 3;

[Explanation of symbols]

1 Image reader 2 Host computer 4 Main memory 12 External memory (backup disk memory) 21
Read data calculation means 22 Main memory free space determination means 23 Data saving means 24 Memory locking means 25 Data input means

Claims (1)

[Claims] 1. In a data input method in which a predetermined amount of data is read out at a constant speed and inputted into the main memory of a computer, read data amount calculation means calculates the amount of data to be read in response to the start of data reading, this means main memory free space determining means for determining whether there is an area large enough to store the amount of data calculated by the main memory; and a data input means for inputting the read data into the main memory after the data has been saved, and a memory lock means for locking data input from other sources during the read data input period. A data input method featuring: