JPH07271517A - Information processor - Google Patents

Abstract

PURPOSE:To improve the data read/write processing performance of an information processor by providing a transfer word counter on an external storage interface (I/F) to transfer only the data that pre effective to a CPU. CONSTITUTION:A transfer word counter is provided on an external storage I/F 5, and a word number that is effective to a CPU 1 is set at the counter. Then only the data that are valid to the CPU 1 are sent to a system bus 12 and a host bus 11, and other data (invalid data included in one block) are not sent to both buses and processed (glanced over) by the I/F 5. Thus the traffic can be suppressed for both buses 11 and 12 and the data transfer time can be shortened. As a result, the processing efficiency of the CPU 1 is improved and the bus occupying time is also shortened. So that the waiting time of other devices can be shortened for the bus using right. Furthermore it is not needed to prepare a buffer area for a main memory in response to the block size of an external storage 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information processing device.

[0002]

2. Description of the Related Art An external storage device such as a hard disk (HD) or an optical disk (OD) used in an information processing device stores data in block (sector) units (for example, 1 block = 512 bytes). Further, the data handled by the central processing unit (CPU) is in word units (for example, 1
Word = 1 byte, etc.). In this way, CP
The storage units handled by U and the external storage device are different. Therefore, when data is transferred between the two, the one with a smaller storage unit (usually the CPU) adds the dummy data and transfers the data according to the one with a larger storage unit (usually the external storage device). I am supposed to do it.

However, the conventional information processing apparatus as described above has the following problems.

First, when reading data from an external storage device or writing data to the external storage device,
Since dummy data that is unnecessary (invalid) for the CPU must be transferred, there is a problem that it takes time to transfer the data.

Further, during the data transfer, the host bus and the system bus are used for the data transfer, so that there is a problem that the bus cannot be used by other devices and the processing efficiency is lowered.

Further, in data transfer with an external storage device, a buffer area matching the block size of the external storage device must be prepared in the main memory (main storage device), and the buffer area on the main memory becomes large. There is a problem.

[0007]

As described above, in the conventional information processing apparatus, there is a problem that processing performance such as data reading / writing is deteriorated.

The present invention has been made to solve the above problems, and an object of the present invention is to provide an information processing apparatus having an improved processing performance such as data read / write.

[0009]

In order to solve such a problem, the invention according to claim 1 uses only data necessary for a central processing unit (CPU) as a main storage device (main memory).
From the external storage device interface,
And a means for generating and adding a shortage for the block size of the external storage device with the external storage device interface.

According to a second aspect of the invention, the central processing unit (C
PU) means for transferring only data necessary for the main memory (main memory) to the external storage device interface, a transfer word number counter provided in the external storage device interface for counting the number of transfer words, and a block of the external storage device A dummy word register for generating and adding dummy data, which is a shortage for the size, and transferring the dummy data to an external storage device.

According to a third aspect of the invention, the central processing unit (C
It has means for transferring only data necessary for the PU) from the external storage device to the main storage device (main memory) and means for discarding data unnecessary for the central processing unit (CPU) at the external storage device interface.

The invention according to claim 4 is the central processing unit (C
PU) The transfer word number counter provided in the external storage device interface for transferring only the data necessary for the external storage device to the main storage device (main memory), and the data unnecessary for the central processing unit (CPU) externally. And a means for discarding the data in the storage device interface.

According to a fifth aspect of the present invention, a central processing unit (C
PU) set the number of valid words in the direct memory access controller (DMAC) and external storage,
It is provided with means for accessing the main memory (main memory) by the number of words and means for generating, adding or reading out data invalid to the central processing unit (CPU) by the external memory interface.

[0014]

In the present invention, the external storage device interface (I / F) is provided with the transfer word number counter. Then, the number of words valid for the CPU is set in the transfer word number counter, only the data valid for this CPU is sent to the system bus or the host bus, and the remaining data (invalid data or insufficient data in one block) Is not sent to the system bus or host bus, but is processed (discarded or created / added) by the external storage device I / F. As a result, the traffic on the system bus and the host bus can be suppressed, and the time required for data transfer can be shortened. Therefore, the processing efficiency of the CPU is improved. In addition, since the bus occupation time is shortened, the time when another device waits for the right to use the bus is shortened. Further, it is not necessary to prepare a buffer area in the main memory according to the block size of the external storage device.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a diagram showing the configuration of an information processing apparatus according to an embodiment of the present invention.

The information processing apparatus shown in FIG. 1 includes a central processing unit (CPU) 1, a main memory (main storage device) 2, a system bus controller 3, and a DMA (direct memory access).
(Direct memory access) Controller (DMAC) 4,
It is composed of an external storage device interface (I / F) 5, an external storage device 6, a host bus 11 and a system bus 12.

The DMA controller 4 requests the stop of the operation of the CPU 1, separates the CPU 1 from the main memory 2, and directly transfers the data between the main memory 2 and the external storage device 6 without going through the CPU 1.

In the present invention, the external storage interface (I / F) 5 is provided with a transfer word number counter. Specifically, in the I / F control circuit of the external storage device I / F,
The same function as the data transfer counter of MA (or CPU transfer unit) is inserted.

The external storage device 6 is composed of, for example, a hard disk (HD) or an optical disk (OD).

First, the read processing in the information processing apparatus shown in FIG. 1 will be described based on the processing conceptual diagram shown in FIG.

As shown in FIG. 2, when transferring (reading) data from the external storage device 6 to the main memory 2, the data required by the CPU is N words, and the storage unit of the external storage device 6 is B words. If there is, the external storage device 6 reads n = (N + B-1) / N (mod B) blocks (calculates the number of blocks).

All the read data are transferred to the main memory 2 up to the (n-1) th block. And
In the n-th block, since only M = N mod B words are required, only the required M words are transferred to the main memory 2, and the unnecessary (BM) words are transferred to the external storage device I /
It is discarded at F5 and is not transferred to the main memory 2.

In the present invention, the external storage device interface (I / F) 5 is used to realize the above-mentioned reading process.
In addition, a transfer word number counter is provided. Then, the number of words valid for the CPU is set in the transfer word number counter, only the data valid for this CPU is sent to the system bus or the host bus, and the remaining data (invalid data in one block) is transferred to the system bus. Or sent to the host bus and processed (discarded) by the external storage device I / F.

Next, the flow of read processing in the information processing apparatus shown in FIG. 1 will be described based on the flow chart shown in FIG.

In the external storage device, n = (N + B-1) / B
Then, the number of blocks is calculated (step 301).

The transfer word number N is set in the transfer word number counter of the DMAC (step 302).

The transfer word number N is set in the transfer word number counter provided in the external storage device I / F (step 30).
3).

The number of blocks n is set in the external storage device and the external storage device I / F (step 304).

When the external storage device and the external storage device I / F are made to read n blocks (step 30)
5), the N words are transferred to and stored in the main memory 2 by the DMAC (step 306).

When the transfer of N words is completed (step 3
07) and notifies the completion of transfer to the CPU (step 30)
8).

The external storage device and the external storage device I / F continue reading until the end of the block, but remain (B-
The M) word is read and discarded by the external storage device I / F 5 (step 309).

Thus, the transfer of n blocks is completed (step 310).

Next, the writing process in the information processing apparatus shown in FIG. 1 will be described based on the processing conceptual diagram shown in FIG.

As shown in FIG. 4, when data is transferred (write processing) from the main memory 2 to the external storage device 6, there are N words of data to be transferred in the main memory 2, and the block size of the external storage device 6 ( Memory unit) is B
If it is a word, n blocks are written to the external storage device 6. Here, the (B × (n−1)) words up to the (n−1) th block are transferred from the main memory to the external storage device 6 via the external storage device I / F5 as in the conventional case, and the last nth block. Then, only the required M words are transferred from the main memory 2 to the external storage device 6, and the (BM) words are generated and added by the external storage device I / F 5 and transferred to the external storage device 6.

In the present invention, the external storage device interface (I / F) 5 is used in order to realize the above-mentioned writing process.
In addition, a transfer word number counter and a dummy word register are provided. Then, the number of words valid for the CPU is set in the transfer word number counter, the value of dummy data (the number of dummy words) is set in the dummy word register, and only the data valid for the CPU is sent to the system bus or the host bus. Data that is insufficient with respect to the block size is processed (created and added) by the external storage device I / F.

Next, the flow of the writing process in the information processing apparatus shown in FIG. 1 will be described based on the flowchart shown in FIG.

In the external storage device, n = (N + B-1) / B
Then, the number of blocks is calculated (step 501).

The transfer word number N is set in the transfer word number counters of the external storage device I / F and the DMAC (step 502).

The value of dummy data (the number of dummy words) is set in the dummy word register provided in the external storage device I / F (step 503).

The number of blocks n is set in the external storage device and the external storage device I / F (step 504).

Writing of n blocks is started in the external storage device and the external storage device I / F (step 50).
5).

N words are stored in the main memory 2 by the DMAC.
From the external storage device I / F and the external storage device (step 506).

When the transfer of N words is completed (step 5
07) and notifies the completion of transfer to the CPU (step 50)
8).

The external storage device I / F generates dummy data of (BM) words and transfers the data to the external storage device (step 509).

Thus, the transfer of n blocks is completed (step 510).

The present invention is not limited to the above embodiment.

For example, in the above-described embodiment, the DMAC between the main memory 2 and the external storage device I / F is independent, but the DMAC does not have to be independent, and the bus controller and the external storage device are not required. The configuration may be included in the I / F or the like.

Further, the CPU may transfer the data instead of the DMAC.

Further, the DMAC does not have to be in the position shown in FIG. 1, but may be in any position as long as it has a function of transferring data between the main memory and the external storage device I / F.

The bus configuration does not have to be the two-bus configuration shown in FIG. 1, and may be a two-bus or more bus configuration.

Further, the positional relationship between the CPU, the main memory, the external storage device I / F and the DMAC is not limited to the position shown in FIG. 1, but may be any positional relationship.

[0053]

As described above, according to the information processing apparatus of the present invention, the traffic of the system bus and the host bus can be suppressed and the time required for data transfer can be shortened. Therefore, the processing efficiency of the CPU can be improved.

Further, since the bus occupation time is shortened, the time for another device to wait for the right to use the bus is shortened.

Furthermore, it is not necessary to prepare a buffer area in the main memory according to the block size of the external storage device.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an information processing apparatus according to an embodiment of the present invention.

FIG. 2 is a process conceptual diagram showing a read process in the information processing apparatus according to the embodiment of the present invention.

FIG. 3 is a flowchart showing a flow of read processing in the information processing apparatus according to the embodiment of the present invention.

FIG. 4 is a process conceptual diagram showing a writing process in the information processing apparatus according to the embodiment of the present invention.

FIG. 5 is a flowchart showing a flow of a writing process in the information processing apparatus according to the embodiment of the present invention.

[Explanation of symbols]

 1 ... Central processing unit (CPU) 2 ... Main memory (main storage device) 3 ... System bus controller 4 ... DMA controller (DMAC) 5 ... External storage device interface 6 ... External storage device 11 ... Host bus 12 ... System bus

Claims (5)

[Claims] 1. A means for transferring only data necessary for a central processing unit from a main storage device to an external storage device interface, and means for generating and adding a deficiency to the block size of the external storage device by the external storage device interface. An information processing device characterized by: 2. A means for transferring only the data necessary for the central processing unit from the main storage device to the external storage device interface, a transfer word number counter provided in the external storage device interface for counting the number of transfer words, and an external storage device. And a dummy word register for generating and adding dummy data, which is a shortage amount to the block size, and transferring the dummy data to an external storage device. 3. A means for transferring only data necessary for the central processing unit from the external storage device to the main storage device, and means for reading out data unnecessary for the central processing device at the external storage device interface. A characteristic information processing device. 4. A transfer word number counter provided in an external storage device interface for transferring only data necessary for the central processing unit from the external storage device to the main storage device, and external data storing data unnecessary for the central processing unit. An information processing device comprising: a device interface for reading and discarding. 5. A means for directly setting the number of words valid for the central processing unit in the memory access controller and the external storage device, and accessing the main storage device by the number of words, and an external storage device for storing data invalid for the central processing unit. An information processing apparatus comprising means for generating, adding, or discarding by an interface.