JPH0214461A - Magnetic disk protection system - Google Patents

Abstract

PURPOSE:To make the power supply small in size by stopping the operation instantly except the write to a magnetic disk device (HDU) and stopping the operation after the end of write during write to one HDU. CONSTITUTION:The power supply 13 is provided with the 1st power output 13b connecting to a CPU 10 and a magnetic disk controller (HDC) 11 and whose voltage is reduced immediately by the momentary interruption or stop of the power supply and with the 2nd power output 13c connecting to the HDC and HDU and whose voltage is drops after a maximum write operating time elapses from the momentary interruption or stop of the power supply. If power momentary interruption or power failure exists during not writing state, the 1st power output 13b of the power supply 13b is decreased immediately and the write is immediately stopped by a reset signal. On the other hand, in the occurrence of momentary interruption or power failure during write, the 1st power output 13b is decreased immediately but the 2nd power supply output 13c is reduced after maximum write operating time elapses and the operation is stopped after the end of write. Thus, the power supply is made small in size.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a control device having a magnetic disk device,
In particular, it relates to magnetic disk protection methods that protect against instantaneous power supply or power outages.

[Conventional technology]

In general, a write operation of a control unit having a magnetic disk device, that is, a write operation from a central processing unit (hereinafter simply referred to as CPU) to a magnetic disk device (hereinafter simply referred to as HDU) is performed by the CPU as shown in Figure 3. After storing data 1 in the memory of the magnetic disk controller (hereinafter referred to as DC), write command 2 is issued to the memory. This write command 2 also includes the write address information of 2. The HDC receives this write command 2 and writes 1 (D
When it is necessary to move the magnetic head of U, a seek command 3 for moving the magnetic head is issued to (2).

When this HDU receives this seek command 3, it moves the magnetic head to the specified position, and when the movement is completed, it issues a seek completion report 4 to T (DC). This seek operation time T1 is a maximum of 80 msec (for example, NEC D3146 type HDU) is required.The HDC requires seek completion report 4.
In response to this, a sector address indicating the write address within the track and a write command 5 are issued to the HDU. [ha)IIXT
Since it is a rotating body, it is necessary to wait for rotation until the specified address is found, and this rotation waiting time T is at most 1
5.5 msec (for example, in the case of ■C made D3146 type T (DU)).

When the HDU finds the specified address, it issues a write start report 6 to the HDC. The IDC receives this write start report 6 and transfers the write data 7 from the memory stored in the HDC to the HDU. The HDU receives this write data T and writes it into ■U, and upon completion, issues a write completion report 8 to the HDC.

Upon receiving this write completion report 8, the controller issues a write completion report 9 to the CPU to complete the write operation.

Therefore, in the past, this type of magnetic disk protection method required a seek operation time of 80m as a countermeasure against instantaneous power interruptions or power outages.
seconds, maximum rotational latency 16.6ms and write time 1
In order to guarantee output retention for a total of 112.2 msec (6.6 msec), & and [J were equipped with a power guarantee function for 100 to 200 msec.

[Problem to be solved by the invention]

The conventional magnetic disk protection method described above requires countermeasures against momentary interruptions and power outages, including seek operations that require large currents, and requires a large number of capacitors or periodic replacement to maintain power output for 100 to 200 msec. The drawbacks are that a battery is required, and the power supply is large and expensive.

[Means to solve the problem]

The magnetic disk protection system according to the present invention is connected to the CPU and IDC of the power supply device, and connects to the first power supply output and the HDH, which are connected to the first power supply output and the HDH, which are connected to the CPU and the IDC, and which decreases immediately in the event of a momentary power outage or stoppage. A second power supply output that decreases after the write operation time has elapsed is provided, and T(DCK
means for storing write data from the CPU to the IU and then outputting a write command; means for monitoring the first power supply output; , has means for outputting a reset signal after the writing is completed when the first power supply output is cut off during writing, and outputting the reset signal simultaneously when the first power supply output is cut off when writing is not in progress.

[Effect]

T (Other than during writing to the DU, the operation will stop immediately upon a momentary power outage or stoppage, and when writing to the HDU, the operation will stop after the writing is completed.

〔Example〕

FIG. 1 is a block diagram showing an embodiment of a magnetic disk protection system according to the present invention. In the figure, 10 is a central processing unit (hereinafter referred to as CPU), and 11 is a magnetic disk control unit (hereinafter referred to as CPU) whose detailed circuit configuration is shown in FIG.
12 is a magnetic disk device (hereinafter referred to as HDC), 12 is a magnetic disk device (hereinafter referred to as HD
), 13 is operated by power input 13m, and CP
This is a power supply device (hereinafter referred to as pow) that outputs a first power output t3b for U and power supply voltage monitoring and a second power output 13e for anal and HDH. After the maximum write operation time has elapsed after the power supply 13b is turned off, the second power supply output 13c is turned off.

In addition, in T (DCl 1 shown in FIG. 2), 14 monitors the first power supply output 13b,
A voltage monitoring circuit that outputs a “1” level when
Reference numeral 15 includes a write data memory 16 and a means for storing write data from the CPU 10 to T (DUl 2 and then outputting a write command to HDUl 2), a reset signal is input to input terminal 15m, and a reset signal is input from output terminal 15b. A magnetic disk control unit outputs a write start signal and a write end signal from an output terminal 15c, 17 is a flip-flop which is set to the write start signal, reset to the write end signal, and indicates the write operation tl; It is a reset control gate that outputs a reset signal when the output of the power supply monitoring circuit 14 becomes "1" when the flip-flop 17 is in a reset state. Further, the maximum write operation time is, for example, the time from write start report 6 to write end report 8 shown in FIG. 3, and is, for example, 16.6 msec of continuous write operation time for one track.

Next, the operation of the magnetic disk protection system with the above configuration will be explained. First, when there is a momentary power outage while a write operation is not in progress, the first power output 13b of 20w13 immediately drops. Therefore, power supply monitoring circuit 1
4 detects that the first power supply output 13b has decreased and outputs the "1" level. On the other hand, flip-flop 17
Since it is not in the write operation, it is in the reset state, and its Q output is "0-1".To be sure of this, the two inputs of the reset control gate 18 are both "1" and a reset signal is output from the output terminal. do. In preparation for this, a reset signal is input to the input terminal 15a of the magnetic disk control section 15, so that it is immediately reset and stops the write operation. Therefore, even during a seek operation that requires a large current, the operation can be immediately stopped. Next, when there is a momentary power interruption or power outage during a write operation, the first
Although the power supply output 13b immediately decreases, the second power supply output 13b
e decreases after the maximum write operation time has elapsed. Therefore, the power supply monitoring circuit 14 detects that the first power supply output 13b has decreased and outputs the "1" level. on the other hand,
Since the flip 70 knob 1T is in the writing operation, it is in the set state, and its Q output is "1". Therefore, the two inputs of the reset control gate 1B are set to rlJ and "0", and no reset signal is output from the output terminal. For this reason, the second power output 13e of the POW 13 is supplied to the HDCjl and the HDU 12 for the maximum write operation time from the time of a power outage unless there is a momentary power outage. As a result, from the start of writing until the end of writing, t(DU
By guaranteeing the operation of the key, it is possible to prevent the destruction of the storage unit of punishment.

〔Effect of the invention〕

As explained in detail above, according to the magnetic disk protection method according to the present invention, when writing to the HDU is in progress, the operation immediately stops due to a momentary power interruption or stoppage of the power supply, while when writing to a By stopping the operation after completion of the operation, the power supply device does not need to guarantee the seek operation that requires large current, and the output holding time can be significantly shortened, making it possible to downsize and lower the price. What effect does it have?

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a magnetic disk protection system according to the present invention, FIG. 2 is a diagram showing a detailed circuit configuration of the magnetic disk control device of FIG. 1, and FIG. 3 explains a write operation. This is a diagram for 10...Central processing unit, 11...Magnetic disk control device, 12...Magnetic disk device, 13...
・Power supply device, 14... Voltage monitoring circuit, 15...
Magnetic disk control unit, 16...Memory for write data, 17...Flip 70 knob, 18...Reset control game CPU Fig. DC DU

Claims (1)

[Claims] In a magnetic disk system that includes a central processing unit, a magnetic disk control unit, a magnetic disk device, and a power supply, the power supply is connected to the central processing unit and the magnetic disk control unit, and has a power supply system that is connected to the central processing unit and the magnetic disk control unit, and has a power supply that is immediately degraded by a momentary power interruption or power outage. The magnetic disk control device has a central processing means for storing write data from the device to the magnetic disk device and then outputting a write command to the magnetic disk device; means for monitoring the first power supply output; It has a means for indicating that a write operation is in progress, a means for outputting a reset signal after the write is completed when the first power supply output is cut off during writing, and a means for outputting the reset signal at the same time as the first power supply output is cut off when writing is not in progress. A magnetic disk protection system featuring: