JPH02267706A - Write circuit for magnetic storage device - Google Patents

Abstract

PURPOSE:To immediately grasp abnormality contents and to speed up the restoring work of data by outputting a write abnormality signal to block the output of a write control signal when the abnormality is generated to a write current. CONSTITUTION:When the voltage of a power source +V1 is made abnormal, an output control signal 111 of a voltage detecting means 50 makes a write control means 10 into an action incapable condition. In such a case, since a write control signal 103 makes a write circuit 20 into a non-action condition regardless of the condition of a write enable signal 102, write currents 104 and 105 are not supplied to a magnetic head 30. For such a reason, an abnormality supervising means 40 judges a write current abnormality, a write abnormality signal 110 is sent, the means 10 is made into the action incapable condition, and simultaneously, a host device is informed of the abnormality of the write circuit. Further, also when a power source -V2 or +V3 is made abnormal, the signal 110 is sent, and the abnormal of the write circuit is reported in the same way. Thus, the abnormality contents can be immediately grasped, and the restoring work of the data can be made speedy.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a write circuit for a magnetic storage device, and particularly to a write circuit that does not take countermeasures against unexpected power cut-off accidents.

[Conventional technology]

As shown in FIG. 2, a write circuit of a conventional magnetic storage device includes write control means 10. Writing means 20. It is composed of a magnetic head 30 and a voltage detection means 50, and receives a write data signal 10 sent from a host device (control device, etc.)
1 is input to the write means 20, and the write enable signal 102 is input to the write control means 1θ.

Further, the output of the write control means 1O is sent to the write means 20, and the output of the write means 20 is sent to the magnetic head 30. Furthermore, the output of the voltage detection means 50 for detecting an abnormality in the voltage of the power supply +v1 is sent to the write control means IO. The operation of the write circuit having such a circuit configuration is such that when the power supply +v1 is normal, the output control signal 111, which is the output of the voltage detection means 50, makes the write control means 10 operational, and the power supply V1 is turned on. If the voltage drops abnormally or is disconnected for some reason, the output control signal Ill
makes the write control means 10 inoperable. Next, when the power supply V1 is normal and the write control means IO is in an operable state, the write enable signal 102 becomes active, so that the write control signal 103, which is the output of the write control means IO, is activated. The writing means 20 is activated and a write current 104105 is supplied to the magnetic head 30 in accordance with the write data signal +01. Also, power supply ■1 is abnormal.
In addition, when the write control means IO is in an inoperable state, the write control signal 103 makes the write means 20 in an inoperable state regardless of the state of the write enable signal 102, so that the magnetic head 30 is not operated. Write current 104105 is not supplied.

[Problem to be solved by the invention]

In the write circuit of the conventional magnetic storage device described above, the power supply V
Countermeasures have been taken against the voltage abnormality of power supply 1, but no countermeasures have been taken against the voltage abnormality of power supply -V2 and power supply V3 supplied to the writing means 20. V
2, or when the voltage of the power supply +V3 abnormally drops or is disconnected, the write current 104.2 supplied to the magnetic head 30.
105 also becomes abnormal, and there is a drawback that recording to a magnetic storage means (for example, a magnetic disk device, a magnetic tape device, etc., not shown) cannot be performed normally. Furthermore, since the write operation is only stopped in the event of a power failure and the higher-level device is not notified, it is unclear whether the write operation ended normally or abnormally, making it difficult to quickly recover data. The disadvantage is that it cannot be done.

[Means to solve the problem]

The present invention also provides a write control means that is supplied with positive and negative voltages from a first power source and a second power source, respectively, inputs a write enable signal, and outputs a write control signal; connected to a power source, the voltage of the first power source decreases,
or a first voltage detection means that sends a first output control signal that prevents output of the write control signal to the write control means when disconnected, the second power supply, and data writing; The magnetic head is supplied with negative and positive voltages respectively from a third power supply connected through the magnetic head.
A write circuit for a magnetic storage device comprising a write means for inputting a data signal and the write control signal and supplying a write current to the magnetic head, the second power supply; the second power source connected to the third power source;
or a second voltage detection means that sends a second output control signal to block the supply of the write current to the write means when the voltage of the third power source is lowered or cut off;
The write current connected to the magnetic head and supplied from the write means is monitored, and if an abnormality occurs in the write current, the write control signal is sent to the write control means. and abnormality monitoring means for outputting a writing abnormality signal to prevent output.

〔Example〕

Next, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention. In FIG. 1, write control means 10. The M sending means 20 and the voltage detecting means 5θ have the same structure as the conventional writing circuit shown in FIG. A voltage detection means 60 for detecting the voltage is connected to the writing means 20, and the writing means 20
The output of is connected to an abnormality monitoring means 40 for detecting an abnormality in the write currents 104 and 105 of the magnetic head 3°. Further, the output of the abnormality monitoring means 4o is connected to the write control means IO.

Next, the operation of this embodiment will be explained. Power supply V1.
When the voltages of the power source -V2 and the power source V3 are all normal, the output control signals 111 and 112 sent from the voltage detection means 50 and 60 respectively are the write control means 10 and the write means 2.
Make 0 operational. Here, when the write enable signal 102 sent from the host device becomes active, the write control signal 103 sent from the write control means 10 to the write means 20 causes the write means 20 to be activated. The writing means 20 applies write currents 104, 10 to the magnetic head 30 according to the write data signal 101 sent from the host device.
Supply 5. At this time, the write abnormality signal 110, which is the output of the abnormality monitoring means 40, maintains the write control means IO in an operable state since the write currents 104 and 105 are normally supplied. Further, when the voltage of the power supply element v1 becomes abnormal, the output control signal 111 which is the output of the voltage detection means 50 makes the write control means 10 inoperable.

In this case, the write control signal 103 makes the writing means 20 inactive regardless of the state of the write enable signal 102, so the write current 104105 is not supplied to the magnetic head 30. Therefore, the abnormality monitoring means 40 connected to the write currents 104 and 105 of the head 30, which are the outputs of the writing means 20, determines that there is a write current abnormality, sends out a write abnormality signal 110, and writes The control means 10 is rendered inoperable, and the host device is notified of the abnormality in the write circuit. Further, when an abnormality occurs in the voltage of the power supply -V2 or the power supply terminal V3, the voltage detection means 60 outputs the output control signal 11.
2 to make the writing means 20 inactive. In this case, when the write enable signal 102 becomes active, the write control signal 103 also becomes active, but since the writing means 20 is already in an inactive state, no write current 104, 105 is supplied to the magnetic head 30. Further, in the same manner as described above, the abnormality monitoring means 40 sends out a write abnormality signal +10 to make the write control means 10 inoperable, and
Notifies the host device of an abnormality in the write circuit.

〔Effect of the invention〕

As explained above, according to the write circuit of the magnetic storage device of the present invention, the write control means and the means for detecting an abnormal drop or disconnection of the power supply voltage of the write means are provided, and when there is an abnormality in these power supplies, , the write means can be made inactive irrespective of the write enable signal, so that the write circuit is supplied with lO... write control means, 20... write means, 30... Magnetic head, 40... Abnormality monitoring means,
50.60... Voltage detection means.

Claims (1)

[Claims] write control means that is supplied with positive and negative voltages from first and second power supplies, inputs a write enable signal, and outputs a write control signal, and is connected to the first power supply. a first voltage detection means for sending a first output control signal to the write control means to prevent output of the write control signal when the voltage of the first power source is lowered or cut off; Negative and positive voltages are respectively supplied from the second power supply and a third power supply connected via a magnetic head for writing data to generate the write data signal and the write control signal. a write circuit for a magnetic storage device, the write circuit being connected to the second power source and the third power source; a second output control signal that sends out a second output control signal that blocks supply of the write current to the write means when the voltage of the second power supply or the third power supply drops or is cut off; A voltage detection means is connected to the magnetic head and monitors the write current supplied from the write means, and when an abnormality occurs in the write current, the write control means detects the write current. 1. A write circuit for a magnetic storage device, comprising abnormality monitoring means for outputting a write abnormality signal that prevents output of a write control signal.