JPH0143396B2 - - Google Patents

Description

Detailed Description of the Invention [Summary of the Invention] The present invention relates to a protection circuit for magnetic bubble memory cassettes. If each cassette is equipped with a drive power supply, if the power to the magnetic bubble memory cassette is turned on when the power to the control means is turned off, the control signal from the control means will not reach the standard level value. Due to such malfunctions, the device of the magnetic bubble memory cassette malfunctions and data and circuits are destroyed. For this purpose,
A magnetic bubble in which a control means power state detection means capable of detecting a power state within the control means is provided in a magnetic bubble memory cassette, and a control signal from the control means is not applied to the magnetic bubble memory etc. based on the output of the detection means. A memory cassette device is provided.

[Industrial application field]

The present invention relates to a magnetic bubble memory cassette device, and more particularly to a magnetic bubble memory cassette device having a detection means within the magnetic bubble memory cassette capable of detecting a power-on or power-off state of a control means.

[Conventional technology]

Generally known magnetic bubble memories include a bubble memory card in which a bubble memory device is integrated with a driving circuit on a printed circuit board, or a bubble cassette system in which a bubble memory cassette is detachably attached to a holder containing a control means. An example of a conventional construction of such a bubble cassette system will be described in detail with reference to FIG. In FIG. 3, reference numeral 1 denotes a control means controlled by a host computer or the like, and includes a bubble memory controller 1a and a control section power supply 1b. 2a, 2b...2n are a plurality of magnetic bubble memory cassettes, and bubble memory devices 2a ₂ , 2b ₂ ...
. _. 2n ₂ , and a drive signal and a device selection signal from the _control means ₁ are applied through a line 3. That is, when a magnetic bubble memory cassette is mounted in a holder having a control means, a control signal such as a device selection signal is applied to the magnetic bubble memory cassette.

[Problem that the invention seeks to solve]

In the bubble memory cassette system described above, the control section power supply 1b on the control means 1 side and each power supply 2 on the magnetic bubble memory cassette 2a, 2b...2n side
If a ₁ , 2b ₁ ... 2n ₁ are in the "off" state at the same time, no problem will occur, but for example, if
When the power supplies 2a 1 , 2b ₁ , . . _. 2n ₁ of the magnetic bubble memory cassette devices 2a, 2b, .
On the magnetic bubble memory cassette device side, even though the bubble memory devices 2a _{2 ,} 2b ₂ . Since the magnetic bubble memory cassettes 2a, 2b, . . . , 2n are given bubble memory selection signals, the bubble memory devices, etc. on the side of the magnetic bubble memory cassettes 2a, 2b, .

[Means for solving problems]

The present invention has been made in view of the above drawbacks,
The purpose of this is to provide a protection circuit within the magnetic bubble memory cassette that uses a signal line between the control means and the magnetic bubble memory cassette to detect when the control means is powered off, thereby preventing the destruction of memory data, etc. A magnetic bubble memory cassette having a magnetic bubble memory device, decoding means for selecting the magnetic bubble memory device, and power supply means for operating the magnetic bubble memory device; The magnetic bubble cassette control means includes a control means having a bubble memory controller for driving and controlling the bubble memory controller, and a power supply means for operating the bubble memory controller, and a power-off detection device for detecting a disconnection state of the power supply means is provided in each of the magnetic bubble cassette control means. A control means power state detection means is provided in the magnetic bubble memory cassette for detecting the power state of the control means based on the power cutoff detection means in the control means, and the control means power state detection means detects the power state of the control means based on the power cutoff detection means in the control means. This is achieved by a magnetic bubble memory cassette device characterized in that the device selection signal to the decoding means is cut off when the device is inserted.

[Effect]

The magnetic bubble memory cassette device of the present invention detects the state in which the voltage of the power supply on the control means side is cut off or turned on by the detection means provided on the magnetic bubble memory cassette device side, and controls the bubble memory cassette from the control means. The signal is placed in a disabled state to prevent the bubble memory device from malfunctioning.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail with reference to FIGS. 1 and 2. FIG. 1 is a circuit diagram of the magnetic bubble memory cassette system of the present invention, and FIG. 2 is a circuit diagram of the control means power state detection circuit shown in FIG. In FIG. 1, the control means 1 is controlled by a host computer or the like, and has a bubble memory controller 1a and a control section power supply (not shown) as in FIG. 3. Furthermore, it has a power-off detection circuit 1c that detects a power-off of the control unit power supply, and the output of the power-off detection circuit is given to the base of a transistor _Tr1 , whose emitter is grounded and whose collector is connected to a voltage source V _M resistance R ₁ , bubble memory controller 1a,
It is connected to the line 3 that transmits the power-off signal 3b. A drive signal 3c and a device selection signal 3b are applied from the bubble memory controller 1a to a plurality of magnetic bubble memory cassettes 2a...2n.

Multiple magnetic bubble memory cassettes 2a...2n
There are multiple bubble memory devices 4 inside each
a, 4b...4n and linear circuits 5a, 5b...5n that drive these plurality of bubble memory devices.
and the device selection signal 3 from the control means described above.
a, and the output of the decoding circuit is the linear circuit 5a, 5b...5
given to n.

On the other hand, the drive signal 3c from the control means 1 is also applied to the linear circuits 5a, 5b...5n. Each magnetic bubble memory cassette 2a...2n of the present invention
has a power source for driving each bubble memory device (not shown) 4a, 4b, . . . 4n similar to that shown in FIG. This detection output is given to the base of the transistor _Tr2 , the emitter is grounded, and the collector is connected to the line 3 for the power-off signal 3b and the control means power state detection circuit 8 for achieving the object of the present invention. The output of the control means power state detection circuit 8 is applied to the decoding circuit 6 to disable the decoding circuit and stop the linear circuit. Second
The figure shows the control means power state detection circuit described above, in which the power-off signal 3b of the control means 1 is taken out from the line 3 and applied to the negative input terminal of the comparator COM, and the reference voltage is applied to the positive input terminal of the comparator COM. It will be done. Resistors R ₂ and R ₃ are voltage dividing resistors, D is a Zener diode, and the voltage source
V _M has stabilized. The output of the comparator COM is given to the buffer BF in the decoding circuit 6,
When the control unit power supply voltage V _M applied to the bubble memory controller 1a decreases, the output of the comparator COM becomes "H" and the linear circuit 5a,
Control signals such as a bias selection signal applied to 5b...5n are blocked by the buffer BF so as not to be applied to the linear circuit. Therefore, even if the control signal from the control means 1 malfunctions due to a power cut, etc., it will not be applied to the linear circuits 5a, 5b, . . . 5n, so malfunctions in the bubble memory device section can be prevented.

〔Effect of the invention〕

As described above, the magnetic bubble memory cassette device of the present invention is provided with a control means power state detection circuit for monitoring the power supply voltage state of the control means side on the magnetic bubble memory cassette side. Incorrect drive signal output,
Even if a device selection signal is applied to the magnetic bubble memory cassette side, it is blocked, so that a magnetic bubble memory cassette device can be obtained in which the bubble memory device does not malfunction.

[Brief explanation of drawings]

Fig. 1 is a system diagram of the magnetic bubble memory cassette system of the present invention, Fig. 2 is a specific circuit diagram of the control means power state detection circuit of Fig. 1, and Fig. 3 is a system diagram showing a conventional magnetic bubble memory cassette system. It is. 1... Control means, 1a... Bubble memory controller, 1b... Control unit power supply, 1c... Power supply detection circuit,
2a, 2b,...2n...magnetic bubble memory cassette, 2a ₁ , 2b ₁ ...2n ₁ ...power supply, 2a ₂ , 2b ₂ ,...
...2n ₂ ...Bubble memory device, 3...Line, 3
a...Device selection signal, 3b...Power cutoff signal, 3c
... Drive signal, 4a, 4b, ...4n... Bubble memory device, 5a, 5b, ...5n... Linear circuit, 6... Decode circuit, 7... Power-off detection circuit, 8
...control means power supply status detection circuit, COM...comparator, BF...buffer.

Claims (1)

[Claims] 1. A magnetic bubble memory cassette comprising: a magnetic bubble memory device; decoding means for selecting the magnetic bubble memory device; and power supply means for operating the magnetic bubble memory device; The magnetic bubble memory cassette control means includes a control means having a bubble memory controller for driving and controlling the bubble memory controller, and a power supply means for operating the bubble memory controller, and a power failure detection device for detecting a disconnection state of the power supply means is provided in each of the magnetic bubble memory cassette control means. The magnetic bubble memory cassette includes a control means power state detection means for detecting the power state of the control means based on the output of the power cutoff detection means in the control means, and the control means power state detection means detects the power state of the control means based on the output of the power cutoff detection means in the control means. A magnetic bubble memory cassette device, characterized in that the device selection signal to the decoding means is cut off when the magnetic bubble memory cassette device is inserted.