JPH04239938A - Magnetic disk controller - Google Patents

Abstract

PURPOSE:To increase a write processing speed in the store in system by backing up a cache memory by a battery circuit to secure the normalcy of data even in the case of stop of power supply. CONSTITUTION:A battery circuit 13 is connected to a cache memory circuit 12 of a magnetic disk controller 3 which is connected to a main storage device 1 through a common data transfer line 2 and controls a magnetic disk device 4.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk control device, and more particularly to a magnetic disk control device with a disk cache that guarantees the normality of data even when power is cut off.

0002

2. Description of the Related Art A conventional magnetic disk control device equipped with a disk cache does not have a function of retaining the contents of the cache memory when the power is turned off.

0003

[Problems to be Solved by the Invention] As mentioned above, the conventional magnetic disk control device with a disk cache uses a store-through method in which data is written to the magnetic disk device at the time of writing in order to guarantee the normality of data in the event of a power outage. This method has the disadvantage that it is not possible to speed up the writing process.

0004

Means for Solving the Problems A magnetic disk control device of the present invention is a magnetic disk control device that is connected to a main storage device through a common data transfer path and controls a magnetic disk device. a magnetic disk control circuit connected to the magnetic disk device to control the magnetic disk device; a cache memory circuit; a battery circuit that supplies power to the cache memory circuit when the power is turned off; It is configured to include a bus control circuit, a DMA transfer control circuit that controls data transfer between the magnetic disk control circuit and the cache memory circuit, and a microprocessor circuit that controls the entire magnetic disk control device.

[0005]

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

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. In FIG. 1, the magnetic disk control device 3 of this embodiment has a common data transfer path (hereinafter abbreviated as "bus").
2, a magnetic disk control circuit 11 that controls the magnetic disk device 4, a cache memory circuit 12, and a battery circuit 13 that supplies power to the cache memory circuit 12 when the power is cut off. , a DMA that controls data transfer between the bus control circuit 10, the magnetic disk control circuit 11, and the cache memory circuit 12.
It includes a transfer control circuit 14 and a microprocessor circuit 15 that controls the entire magnetic disk control device 3 .

The main storage device 1 and the magnetic disk control device 3 are interconnected via a bus 2. In the write process, data read from main memory 1 is written to cache memory circuit 12 via bus 2 and bus control circuit 10 under the control of DMA transfer control circuit 14 . A completion report is made at the time the data is written to the cache memory circuit 12. When there is no more room in the cache memory circuit 12, data is read from the cache memory circuit 12 under the control of the DMA transfer control circuit 14 and written to the magnetic disk device 4 via the magnetic disk control circuit 11. When the power is turned off, the data in the cache memory circuit 12 is held by the battery circuit 13, and when the power is turned on again, the data held in the cache memory circuit 12 is
Use the data as is.

[0008]

As explained above, according to the magnetic disk control device of the present invention, backup can be performed using the battery circuit, so the normality of data is guaranteed even when the power is turned off, and by using the store-in method, write processing can be performed. Speeding up is possible.

[Brief explanation of the drawing]

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

[Explanation of symbols]

1 Main memory 2 Common data transfer path 3. Magnetic disk control device 4 Magnetic disk device 10 Bus control circuit 11 Magnetic disk control circuit 12 Cache memory circuit 13 Battery circuit 14 DMA transfer control circuit 15 Microprocessor circuit

Claims (1)

[Claims] 1. A magnetic disk control device that is connected to a main storage device through a common data transfer path and controls a magnetic disk device, comprising: a bus control circuit that controls the common data transfer path; and a bus control circuit that is connected to the magnetic disk device. a magnetic disk control circuit that controls the magnetic disk device, a cache memory circuit, a battery circuit that supplies power to the cache memory circuit when the power is turned off, the bus control circuit, the magnetic disk control circuit, and the cache memory. DMA that controls data transfer to and from the circuit
A magnetic disk control device comprising a transfer control circuit and a microprocessor circuit that controls the entire magnetic disk control device.