JPS62162275A - Magnetic disk controller - Google Patents

Abstract

PURPOSE:To shorten a rotation waiting time by calculating an end sector obtained by adding the number of sectors up to the sector starting reading or writing operation to the number of sectors to be executed and executing the operation of a magnetic disk whose end sector value is smaller than any one of starting sector values of plural magnetic disk devices with priority. CONSTITUTION:A microprocessor 20 loads the read starting sector No. of a magnetic disk device 200 and the number of sectors to be executed in address X and address X+1 of a local memory respectively. Then, the microprocessor 20 outputs a sector searching instruction for the magnetic disk device 200 to a magnetic disk control circuit 10 and loads the sector No. to address X+2 of the memory 30. Then the contents of the address X+2 of the memory 30. Then the contents of the address X+2 are subtracted from that of address X, the subtracted value is loaded to the address X+3 of the memory 30, the contents of the address X+1 is added to the contents of the address X+3, and the added value is loaded to address X+4. Similarly to X, the added contents are loaded to address Y+4 and the contents of the address Y+4 are compared with that of address Y+3.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic disk control device used in an information processing device.

[Conventional technology]

Conventionally, in a magnetic disk control device that controls two or more fixed sector type magnetic disk devices that have a sector ID (identification code) on the medium to identify each sector, a When a read or write command is input, the commands can be processed in the order in which they are input or in the order of the device addresses of the magnetic disk drive.

[Problem that the invention seeks to solve]

In the magnetic disk control device described above, each time one instruction is executed, it is necessary to start with a search operation for the first sector of the sectors to be read or written.
It takes an average of 1/1 to complete the search operation for the first sector.
``' This method requires time for the two-rotation disk to rotate, so-called rotation waiting time, and there is a drawback that reading or writing operations cannot be performed during this time.

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic disk control device that shortens the conventional rotation waiting time and quickly finishes reading or writing operations.

[-Means for Solving the Problems] The present invention provides a magnetic disk control device in which a central processing unit controls a plurality of fixed sector type magnetic disk devices that store sector identification codes on disks.
A bus control circuit that sends and receives signals and data to and from the central processing unit, a magnetic disk control circuit that sends and receives signals to and from each of the magnetic disk devices, and these bus control circuits and magnetic disk control circuits. and a local memory connected to the microprocessor, and when a read or write command is input to each magnetic disk device, the sector identification of the magnetic disk device to which this instruction is input is provided. Read the code from the disk, calculate the number of sectors up to the sector where the read or write operation starts, calculate the end sector by adding the value of the start sector and the sector function that continuously executes the above operation, and calculate the end sector value by adding the value of the start sector. The present invention is characterized in that when the value of the start sector of a magnetic disk drive is smaller than any of the values, the read or write operation to the magnetic disk drive whose end sector value is smaller is executed with priority.

Example] Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram of a system including one embodiment of the present invention. The magnetic disk control device 100 includes a magnetic disk control circuit 10, a microprocessor 20, a local memory 30, and a bus control circuit 40.

Further, the magnetic disk control device 100 is connected to a magnetic disk device 200 and a magnetic disk device 201, and is also connected to a central processing unit 400 and a main storage device 500 via a bus 300.

FIG. 2 is a diagram showing an example of the format of the sector ID shown in FIG. As shown in the figure, this sector ID includes the 5YNC (synchronization) byte that detects synchronization, the FLAG (flag) used by software, the cylinder number that indicates the disk cylinder number, and the disk. The I-U-TSUK number that indicates the track number, the sector number that indicates the sector number of the disk, and the CR that indicates the cyclic redundancy check code.
It consists of c.

The operation of the magnetic disk control device 100 configured in this manner is as follows. A read command from the central processing unit 400 to the magnetic disk device 200 and the magnetic disk device 2
If a write command for 01 is input to the magnetic disk control device 100 via the bus 300, the microprocessor 20 sets the read start sector number for the magnetic disk device 200 at address At the same time, the write start sector number for the magnetic disk device 201 is loaded into the Y address of the local memory 30, and the number of sectors to perform the write operation is loaded into the Y+1 address. Next, the microbrosé source 20 is the magnetic disk control circuit 1.
0, a sector search command for the magnetic disk device 200 is output.

Magnetic disk control circuit 10 that started the sector search command
When the index pulse or sector pulse from the magnetic disk device 200 arrives, it starts an operation to search for 5YNCbyI. in order to recognize the sector ID shown in FIG. When this 5YNCby1~ is recognized, the magnetic disk control circuit 10 skips the FLAG byte, cylinder number, and track number, inputs the sector number, and executes the CRe check operation. If this CRC check results in no error, the magnetic disk control circuit 1
0 outputs the sector number to the microprocessor 20 and ends the operation.

When the sector number is input, the microprocessor 20 loads the sector number into address X+2 of the local memory 30. Similarly, the microprocessor 20 outputs a sector search command for the magnetic disk device 201 to the magnetic disk control circuit 10, and
When the sector search operation at 0 is completed and the sector number is input, the sector number is loaded into address Y+2 of the local memory.

Next, the microprocessor 20 stores the local memory 30
The contents of address X and the contents of address X+2 are read from the contents of address X, the contents of address X+2 are subtracted from the contents of address Note that if the value to be loaded is negative, the number of sectors per Lulinda is added and then loaded to address X+3 of the local memory 30. Next, the microprocessor 20 reads address X+ and the contents of address X+3 from the local memory 30,
Add the contents of address X-ML1 and the contents of address X-1-3 and load the value to address X+4.4 Similarly, micro7
The 0 setter 20 subtracts the contents at address Y+2 from the contents at address Y in the local memory 30, loads it into address X+3, and loads it into address Y+3.
Add the contents of address X + 3 to the contents of address 1 and set the value to Y
Load +44 address 7 Next, the microprocessor 20 loads the local memory 30.
reads out the contents of address X+3 and compares the contents of address Y10/1, and if the contents of address X+4 is smaller than the contents of address X+3, starts the write operation for the magnetic disk device 201, If the content of the address is greater than the content of address X+3, a read operation for the Ia disk device 200 is started. That is, read and write operations are performed on a magnetic disk device with a small end sector value. [Effects of the Invention] As explained above, by adopting the magnetic disk control device of the present invention, This has the effect that reading or writing operations for two or more magnetic disk devices connected to a magnetic disk control device can be completed more quickly than in the conventional case.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a diagram showing an example of the format of the sector ID shown in FIG. DESCRIPTION OF SYMBOLS 10... Magnetic disk control circuit, 20... Micro 70 setter, 30... Local memory, 110...
Bus control circuit, 100... magnetic disk control device, 2
00.201...Magnetic disk device, 300...Bus, 400...Central processing unit, 500...Main storage device.

Claims (1)

[Claims] In a magnetic disk control device in which a central processing unit controls a plurality of fixed-sector type magnetic disk devices that store sector identification codes on the disks, bus control is used to exchange signals and data with the central processing unit. circuit and
A magnetic disk control circuit that sends and receives signals to and from each of the magnetic disk devices, a microprocessor that controls these bus control circuits and the magnetic disk control circuit, and a local memory connected to the microprocessor, When a read or write command is input to each magnetic disk device, the sector identification code of the magnetic disk device to which this command was input is read from that disk, and the number of sectors up to the sector where the read or write operation starts is calculated. calculate the end sector by adding the number of sectors for which the above operation is to be continuously executed and the value of the start sector; and if the value of this end sector is smaller than any of the values of the start sector of these magnetic disk devices, the value of the end sector is determined. 1. A magnetic disk control device characterized in that a read or write operation for a small magnetic disk device is executed with priority.