JPS63213020A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To reduce the load on a host device against a double writing state by providing a memory circuit to a magnetic disk device. CONSTITUTION:A disk control part 4 supplies a command via an interface part 1 to perform a writing operation to a magnetic disk 5 from a host device. Then the part 4 sets the value of an address counter in a memory circuit 2 at 0 via a memory control signal 56 and at the same time sets a memory under a writable state. Furthermore the part 4 functions to deliver the write data A52 to the write data B54 by a switch signal 55. Then the write data is delivered to the data A52 from the host device and then sent to the part 4 via a switch circuit 3. Thus this data is written into the disk 5 as well as the circuit 2.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to the reliability of data on magnetic disks, and more particularly to data security by double banding.

Conventional technology Conventionally, when performing double banding on a magnetic disk, the upper group @
A method is used in which the magnetic disk processing unit (generally a magnetic disk processing unit) issues a write instruction to the magnetic disk unit twice, and a method in which the magnetic disk unit itself performs double banding with only one write instruction is not used. It wasn't.

Problems to be Solved by the Invention The conventional magnetic disk device described above is
Since double banding is not performed by the second write instruction, the host device
The disadvantage is that the host device has to issue write instructions every time, which puts a heavy burden on the host device and slows down the processing speed.If the write data from the host device is delayed, an overrun error usually occurs and the processing The disadvantages are that the process has to be executed again, and that high-speed performance is required in terms of the performance of the host device.

The present invention has been made in view of the above-mentioned conventional situation,
Accordingly, an object of the present invention is to provide a novel magnetic disk device that makes it possible to eliminate the above-mentioned drawbacks inherent in the conventional technology.

Means for Solving the Problems In order to achieve the above objects, a magnetic disk device according to the present invention includes an interface unit that controls an interface with a host device, and a strobe and data output from the interface unit. A memory circuit that has a function of writing data into memory and has a built-in address counter, and a switching circuit that inputs each data and strobe output from the memory circuit and the interface section and outputs either one of the data and strobe. and a switching signal for instructing switching to the switching circuit, a memory control signal for instructing address control, reading, and writing to the memory circuit, and successive data to be output to the interface section, and output from the switching circuit. The disk controller is configured to include data, a strobe, and a disk control section that inputs command signals output from the interface section and controls the magnetic disk.

Embodiment Next, a preferred embodiment of the present invention will be specifically explained with reference to the drawings.

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

Referring to FIG. 1, reference number 1 is an interface section that controls the interface with a host device.

Reference numeral 2 denotes a memory circuit which inputs the data and strobe output from the interface section 2 and sequentially writes them into the memory, and has a built-in address counter. Reference numeral 3 designates a switching circuit which outputs one of the data and strobe output from the memory circuit 2 and the data and strobe output from the interface section 1 to the disk control section 4 in accordance with the instruction of the switching signal 55.

4 outputs a switching signal 55 to the switching circuit 3 , outputs a memory control signal 56 to the memory circuit 2 , or outputs successive data 57 read from the magnetic disk 5 in accordance with the command signal 51 from the interface section 1 . The output of
Or the data output from the switching circuit 3 is transferred to the magnetic disk 5.
This is a disk control unit that performs writing operations, and one magnetic disk 5 is connected under it by one spindle.

The signal line 51 is a command signal sent from the interface section 1 to the disk control section 4, and the signal line 52 is write data A including a strobe signal sent from the interface section 1 to the memory circuit 2 and switching circuit 3. A line 53 is memory output data sent from the memory circuit 2 to the switching circuit 3, and a signal line 54 is write data B sent from the switching circuit 3 to the disk control section 4.

Further, a signal line 55 is a switching signal outputted from the disk control unit 4 to the switching circuit 3, and a signal line 56 is a switching signal output from the disk control unit 4 to the memory circuit 3 for controlling address setting memory write permission, memory read instruction, etc. The signal line 57 is a read data signal that sends data read from the magnetic disk 5 to the interface unit 1.

Next, the operation will be explained.

When the disk control unit 4 receives a command to write to the magnetic disk 5 from the host device through the interface unit 1, the disk control unit 4 sets the value of the address counter inside the memory circuit 2 to 0 using the memory control signal 56. and make the memory writable. Further, the disk control section 4 sets the write data A52 to be outputted as the write data B54 using the switching signal 55. Thereafter, when the write data is output from the host device as write data A52 through the interface section 1 along with the strobe signal, the data is sent to the disk control section 4 through the switching circuit 3 and written onto the magnetic disk 5. At the same time, the same data is written to the memory circuit 2 as well.

When the write operation is completed, the disk control section 4 sets the memory output data 53 to be outputted to the write data B54 using the switching signal 55, and also sets the address of the memory circuit 2 using the memory control signal 56. After setting the counter to O again and putting the memory in a write-inhibited state, control is performed so that the data written first is sequentially outputted to the memory output data 53. Then, the sequentially read data is written again on the magnetic disk 5 at a different position from the position where it was previously written.

Here, there is no particular stipulation for another location, but for data management purposes, when the head number is an even number, the area for direct writing is the area where the head number +1 is the area for writing from memory for the second time. Let's temporarily set and explain.

Therefore, in this case, the control on the magnetic disk side when writing data for the second time to the magnetic disk only requires adding 1 to the head number.

Furthermore, if the write data from the host device is delayed, an overrun flag is set within the disk control unit 4 and processing continues. When the write operation is completed, the data from the memory is written to the area with the head number +1 as in the previous operation, but after that, if the overrun flag is set, the data from the memory is written again with the head number -1. write to the specified area (that is, the direct write area). In this case, the occurrence of an overrun may or may not be reported to the higher-level device, but the higher-level device does not need to retry in response to this report.

As described in detail, according to the present invention, by providing a magnetic disk device with a memory circuit and disabling means for controlling it, it is possible to not only reduce the load on the dual band of the host device, but also to reduce the load on the dual band of the host device. This has the effect of eliminating overrun errors during writing, which are common in magnetic disk drives.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention. 100. Interface section, 200. Meboshi circuit, 31
0. switching circuit, 410. Disc control section, 50
6. magnetic disk, 51. , ,command signal, 52
．． , ,Write data A, 53. , , memory output data, 54. , ,Write data B, 55. , . switching signal, 56. , , memory control signal, 57. ,
' , read data

Claims (1)

[Claims] an interface unit that controls an interface with a host device; a memory circuit that has a function of inputting the strobe and data output from the interface unit and writing data into the memory and has a built-in address counter; the memory circuit and the interface; a switching circuit that inputs each data and strobe output from the section and outputs one of the data and strobe, a switching signal that instructs the switching circuit to switch, and an address control, read, and write instruction to the memory circuit; and a disk control section that outputs read data to the interface section and a memory control signal for controlling the magnetic disk by inputting data output from the switching circuit, a strobe, and a command signal output from the interface section. A magnetic disk device characterized by: