JPH0578859B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to a sector buffer control method for a disk control device, and more particularly to a data transfer processing method between a system bus and a disk device.

Prior Art Conventionally, this type of disk control device has been designed to handle the maximum amount of data that can be handled in one command as a data buffer in order to compensate for the difference in transfer speed and asynchronous operation between the system bus and the disk device in data transfer processing. It is generally configured with an all-sector buffer or FIFO (First in First out) that stores data.

When configured with all sector buffers, data transfer with the disk device must be started after all data transfer with the system bus has been completed, or data transfer with the system bus must be started after data transfer with the disk device has been completed. It will not happen. Therefore, the time required for one command is the sum of each data transfer time, which not only requires a lot of processing time, but also limits the capacity of the disk controller due to the large capacity of the sector buffer. , and has the disadvantage that the amount of circuitry increases.

In a disk control device configured with FIFO, which can perform data transfer processing between a disk device and a buffer at the same time as data transfer processing between a system bus and a buffer, transfer data is not stored within the disk control device. If there is an error in transferred data, it is impossible to determine whether the error was transferred between the disk device and the buffer or between the buffer and the system bus. Circuit failure analysis is difficult.

In addition, when copying data including data changes between different disk devices connected to the same disk device or the same disk control device, whether the disk device is configured as an all-sector buffer or FIFO, A means for transferring read data once to a main storage device via a system bus, and then writing the data from the main storage device again via a system bus to the same disk device or a different disk device connected to the same disk control device. It is common to take Therefore, not only does it require more processing time to use the system bus twice, but also the system bus cannot be used by other controllers during the time when the disk controller is using the system bus. Therefore, there is a drawback that the data transfer processing capacity of the system is reduced, and there is a possibility that data may be transferred erroneously during two system bus transfers, resulting in the copying of erroneous data. .

OBJECTS OF THE INVENTION An object of the present invention is to provide a sector buffer control method that allows data transfer processing to be performed with a disk device at the same time as data transfer processing with a system bus.

Another object of the present invention is to provide a sector buffer control method that allows easy circuit failure analysis.

Still another object of the present invention is to provide a sector buffer control method that can prevent erroneous data copying by improving data transfer processing capacity between different disk devices.

Composition of the Invention According to the present invention, there is provided a sector buffer control method provided between a disk device and a system bus. an instruction means for instructing data transfer between the system bus and the sector buffer; and a sector buffer for switching data transfer with the disk device to either one of the first and second sector buffers. a switching means;
and address counter means for specifying an address of the sector buffer, and when the instruction means instructs data transfer between the system bus and the sector buffer, by specifying the sector address of the address counter means, Performing data transfer processing for one sector between the first sector buffer and the system bus, during which processing processing for transferring one sector worth of data between the second sector buffer and the disk device, etc. In response to the completion of data transfer processing for one sector, the buffer switching means controls switching between the disk device and the sector buffer to which data should be transferred, and the instruction means controls the data transfer between the system bus and the sector buffer. When no instruction is given, the data transfer process for one sector between the first sector buffer and the front-filling disk device is executed by specifying the sector address of the address counter means, and the data for this one sector is transferred. There is obtained a sector buffer control method characterized in that the buffer switching means switches and controls the sector buffer to which data is to be transferred to the disk device in response to the completion of the transfer process.

Embodiments Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention. In Figure 1, two sector buffers 1 and 2 are provided to store data for multiple sectors, and addresses can be set by a program to indicate that a specified amount of data is stored in each sector buffer 1 and 2. flag 5.
Counters 3 and 4 are provided corresponding to sector buffers 1 and 2, respectively.

Specifies the read and write states of the two sector buffers 1 and 2, distinguishes whether they are used for data transfer with the system bus 12 or data transfer with the disk devices 10 and 11, and determines the data transfer state. Controlled sector buffer switching circuit 7
is provided. Also, sector buffers 1 and 2
Flip-flop 8 for specifying by program whether or not to transfer data between and system bus 12
A controller 9 for controlling data transfer with the disk devices 10 and 11, and disk devices 10 and 11 connected to the controller 9 are provided.

The case where data is read from the disk device 10 and transferred to the system bus 12 will be explained as an example. First, when the flip-flop 8 is set to logic "1", that is, data transfer with the system bus 12 is specified, and a read command is given to the disk controller, the counters 3, 4, flags 5, 6, and sector buffer switching circuit 7 are initialized. be converted into The data read from the disk device 10 by the controller 9 is sequentially stored in the sector buffer 1 designated by the sector buffer switching circuit 7 via the internal bus 13 while the counter 3 counts.

When the data transfer for one sector is completed, the flag 5 becomes logic "1" and the data transfer process is temporarily stopped. At the same time, the sector buffer switching circuit 7 is reversed to switch the sector buffer to be stored, and the data collection from the disk device 10 is restarted, and the counter 4 starts counting while data is stored in the sector buffer 2 in the same manner as above. It will be done.

At this time, flag 5 indicating the amount of data in sector buffer 1 used for data transfer with system bus 12 is set to logic "1", and flip-flop 8 specifies that data transfer with system bus 12 is to be performed. Therefore, sector buffer 1
is in a state where data can be transferred with system bus 12, and therefore data is transferred from sector buffer 1 to system bus 1.
As soon as the data transfer to 2 starts, the counter 3
is being counted.

That is, at this point, the process of storing data from the disk device 10 into the sector buffer 2,
A process of transferring data from sector buffer 1 to system bus 12 is being performed at the same time. Moreover, the data transfer speed with the system bus 12 is determined only by the usage status of the system bus 12, without depending on the transfer speed of the disk device 10 and the sector buffer 2, as long as it is within one sector processing time of the data device 10. be done.

Data transfer to the system bus 12 is performed sequentially, and when the flag 5 of the counter 3 becomes logic "0", it means that the data transfer for one sector has been completed. Therefore, data transfer with the system bus 12 is interrupted, and in response to completion of data transfer processing from the disk device 10 to the sector buffer 2, the flag 6 becomes logic "1" and the sector buffer switching circuit 7 is inverted. It will be in a state of waiting.

By repeating the above operation for the number of sectors given by the command, data transfer with the disk device 10 and data transfer with the system bus 12 can be performed simultaneously.

On the other hand, in FIG. 2 showing an embodiment of the counter 3, the counter 3 is a counter 1 that counts an upper address indicating one sector among a plurality of sectors.
4, a counter 15 that counts a lower address indicating an area within one sector, and an inverter 1.
6, an OR gate 17, and an AND gate 18.

When the flip-flop 8 is set to logic "1", that is, designated to perform data transfer with the system bus 12, the upper address is the disk drive 10.
It is counted when one sector worth of data is transferred to both the system bus 12 and the system bus 12. That is, when the flip-flop 8 is set to logic "1", when a carry from the counter 15 at the lower address is generated by the inverter 16, OR gate 17, and AND gate 18 when the flag 5 is logic "1". The upper address counter 14 counts accordingly.

First, when the data read from the disk device 10 is sequentially stored in the sector buffer 1, only the lower address is counted, and when the data transfer for one sector is completed, a carry of the counter 15 of the lower address is generated. , flag 5 is logic "0" and sector buffer 1 has not yet transferred data to system bus 12, so the upper address is not counted at this point.

After a carry occurs in the counter 15 of the lower address, when the flag 5 becomes logic "1" and the sector buffer switching circuit 7 is inverted, the sector buffer 1 starts data transfer with the system bus 12, and only the lower address is transferred until the transfer of one sector is completed. count. When the data transfer with the system bus 12 for one sector is completed and a carry is generated in the counter 15 of the lower address, since the flag 5 is logic "1", the upper address is counted and the next sector area is At the same time as the designation, flag 5 becomes logic "0". FIG. 3 shows the timing of the operations described above.

The counter 4 also has the same configuration as the counter 3, and is counted after the sector buffer 2 transfers data to both the disk device 10 and the system bus 12.

With the above control, multiple sectors of transfer data are saved in one sector buffer, so if the transfer data is incorrect, the program will read out the sector buffer address to counters 3 and 4. By setting and reading data, the stored transfer data can be read. Therefore, it is possible to determine whether the error occurred in the transfer between the disk device and the sector buffer or the error in the transfer between the sector buffer and the system bus, and it is possible to easily analyze the failure of the circuit.

The operation when writing data to a disk device is basically the same as when reading, except for the direction of data transfer, and the explanation thereof will be omitted.

Next, from the disk device 10 to the disk device 11
An example of copying data to a computer without using the system bus 12 will be described with reference to FIGS. 4 and 5. In the case of data copying, when the flip-flop 8 is reset to logic "0" to specify not to perform data transfer with the system bus, and a command to read data from the disk device 10 is given,
Similarly to the case where data is read from the disk device and transferred to the system bus, the data read from the disk device 10 is sequentially stored in the sector buffer 1 designated by the sector buffer switching circuit 7 via the internal bus 13 and transferred to the counter 3. is being counted.

When the data transfer for one sector is completed, the sector buffer switching circuit 7 is reversed, the sector buffer in which the data is stored is switched, and the receiving of data from the disk device 10 is resumed, and the data is transferred to the sector buffer 2. The counter 4 continues to count while being stored. At this time, as a different operation from the case of transferring data to the system bus, as shown in FIG. When the sector buffer switching circuit 7 is inverted, flag 5 or flag 6 is reset to logic "0" at that point, and in FIG. 8 is logic "0", counters 3 and 4 are controlled to count when a carry from counter 15 at a lower address occurs, regardless of the states of flags 5 and 6. Therefore, when data transfer for one sector is completed between the disk device 10 and sector buffer 1 or sector buffer 2, the upper address is counted and the next sector area is specified without data transfer with the system bus 12. That will happen.

Due to the above control, the disk device 1 is transferred without data transfer with the system bus 12.
The data read from 0 is transferred to sector buffers 1 and 2.
It is possible to sequentially store the data in the sector buffers 1 and 2, and to leave the transfer data for the sectors of sector buffers 1 and 2 in sector buffers 1 and 2 per one instruction.

Once the data for the number of sectors given by the command has been stored in sector buffers 1 and 2, if a command is given to write the data to the disk device 11 with the flip-flop 8 set to logic "0", then the data shown in FIG. As shown, flags 5 and 6 are unconditionally set to logic "1", that is, data to be transferred is stored in sector buffers 1 and 2. When data transfer for one sector is completed between sector buffer 1 or sector buffer 2 and disk device 11, flag 5 or flag 6 is reset to logic "0", but when sector buffer switching circuit 7 is inverted, at that point By controlling the flag to be set to logic "1", data can be written to the disk device 11 without using the system bus 12. as a result,
Data can be copied from the disk device 10 to the device 11 without using the system bus 12. If copying involves changing data, after all data read from the disk device 10 is stored in sector buffers 1 and 2,
The program sets the address of the sector buffer in which data is to be written to the counters 3 and 4, and writes the data. This allows the data stored in the sector buffer to be changed, and then by giving a command to write data to the disk device 11 with the flip-flop 8 set to logic "0",
Copying with data changes is possible.

Effects of the Invention As explained above, according to the present invention, a sector buffer that can each store data for a plurality of sectors is divided into two systems, and transfer data for a plurality of sectors is left in each sector buffer. By making it possible to obtain the history of discrepancies, it is possible to perform data transfer processing with the disk device at the same time as data transfer processing with the system bus, reducing processing time without increasing the amount of circuitry. Moreover, there is an effect that circuit failure analysis can be easily performed. In addition, it is possible to copy data, including data changes, between different disk devices connected to the same disk device or the same disk control device, without reducing the data transfer processing capacity of the system and without making mistakes. This has the effect of preventing data from being copied.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is a diagram showing a specific example of the counter section in FIG. 1, and FIG. 3 is a time chart showing an example of data transfer between a disk device and a system bus. , 4 and 5 are time charts showing examples of data copying between disk devices. Explanation of the symbols of the main parts, 1, 2... Sector buffer, 3, 4... Counter, 5, 6... Flag,
7... Sector buffer switching circuit, 8... Flip-flop, 9... Controller, 10, 11...
Disk device, 12... System bus, 13...
internal bus.

Claims (1)

[Claims] 1. A control method for a sector buffer provided between a disk device and a system bus, comprising first and second sector buffers each capable of storing one sector worth of data, which is a read/write unit of a disk, for a plurality of sectors; an instruction means for instructing data transfer between the system bus and the sector buffer; and an instruction means for instructing data transfer between the system bus and the sector buffer;
and a second sector buffer, and address counter means for specifying an address of the sector buffer, and the instruction means instructs data transfer between the system bus and the sector buffer. 1, data transfer processing for one sector is performed between the first sector buffer and the system bus according to the sector address instruction of the address counter means, and during that time, data transfer processing between the second sector buffer and the disk device is performed. In response to the completion of the data transfer process for one sector, the buffer switching means switches and controls the sector buffer to which data is to be transferred between the disk device and the sector buffer. When data transfer between the system bus and the sector buffer is not instructed by the instruction means, one sector between the first sector buffer and the disk device is transferred by the sector address instruction of the address counter means. The sector buffer is characterized in that the data transfer process for one sector is executed, and in response to the completion of the data transfer process for one sector, the buffer switching means controls switching between the disk device and the sector buffer to which data is to be transferred. control method.