JPS59162607A - Magnetic storage device - Google Patents

Abstract

PURPOSE:To restore the gain of an amplifier, which is adjusted for rereading, to a standard gain after rereading by storing the standard gain, which is adjusted with a DGC (data gain control) signal, in a magnetic storage device. CONSTITUTION:When a storage medium 9 is set, the DGC signal is written and read. At this time, a control circuit 6 sets a gain of an amplifier 4 through a gain control circuit 7 so that an output level for the DGC signal is a prescribed certain value (standard read output level). This gain is the standard gain, and it is stored in a storage part 8 by the control circuit 6. If a read error is detected, the gain control circuit 7 changes the gain of the amplifier 4 in accordance with an indication of a higher rank controller 1. After rereading, the higher rank controller 1 sets the standard gain in the storage part 8 to the amplifier 4.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a magnetic storage device such as a magnetic tape device or a magnetic disk device.

([3] Background of the Technology For example, in a large-capacity magnetic storage device, a large number of magnetic tapes housed in cartridges are stored in a storage wall, and a desired magnetic tape is taken out from the storage wall and used as needed. In such a magnetic storage device in which a large number of storage media are exchanged and used, in order to prevent the signal reading level from changing even if the storage medium is exchanged, the storage medium is turned off before writing/reading data 9. DGC (Data Galn Control) is placed in a predetermined area at the beginning of the storage medium.
A variable gain amplifier is provided for writing a signal, referred to as a signal, and for amplifying a read signal obtained by a read head, the output level of the amplifier for the DGC signal being a predetermined value. The gain of the amplifier is adjusted by 2.

However, due to a temporary abnormality in the magnetic storage device or a partial performance drop in the storage medium, the reading output may be abnormally reduced, which may result in a graining error 9.

In such cases, read! As part of the D114p rounding procedure, the data in the portion where the read IA9 occurred is re-read, and one of the techniques at this time is to increase the gain of the amplifier above the gain adjusted using the DGC signal. However, by lowering the value to 1, reading errors are prevented from occurring.

(C) Prior Art and Problems After performing rereading by changing the gain of the amplifier as part of the read error recovery procedure, the gain of the amplifier is changed to the original value, i.e., i, lAI using the DGC signal.
It is necessary to return to the original gain (hereinafter referred to as standard gain).

For this reason, conventionally, the standard gain or the history of gain adjustment made to the multiplier for rereading has been stored in the upper control device of the magnetic storage device.

However, the standard gain is determined by the alignment between the magnetic storage device and the storage medium.If the upper leg restraint device controls multiple magnetic storage devices, or even if multiple central processing units control the same magnetic storage device. In such cases, the same magnetic storage device is often under the control of multiple higher-level controllers in order to share the standard gain or gain adjustment history. there were.

(2) Object of the Invention An object of the present invention is to make it possible to reliably return the standard gain to the standard gain after the magnetic storage device, rather than outside the magnetic storage device as in the conventional example.

(G) Structure of the Invention The magnetic storage device of the present invention uses a magnetic recording medium as a storage medium, and includes a variable gain amplifier that amplifies read multiple signals obtained from the storage medium, and a variable gain amplifier that amplifies the read multiple signals obtained from the storage medium, and and a means for changing the gain of the amplifier in the recovery process of the failure recovery process, the gain of the amplifier being set to a predetermined value for each of the storage media. A storage unit is provided for storing the predetermined gain value to be set, and the gain value is reset to the predetermined gain value stored in the storage unit after the error recovery process is completed.

(g) Examples of the Invention The gist of the present invention will be specifically explained below by way of practical examples.

The figure shows a block diagram of an embodiment of the present invention, in which 1 is a host control device that controls a magnetic storage device, 2 is an interface circuit, and 3, 6, and 7 are for setting the gain of an amplifier 4 to a value of F9T for each storage medium. 3 comprising means for setting and changing the gain of the amplifier 4 in rereading for the abduction error recovery process;
4 is a gain amplifier that amplifies the read signal obtained from the storage medium described later; 5 is the reading υ head; and 6 is the determination of the standard gain for each storage medium after 10 readings. A control circuit that controls processing, etc.; 7 is a gain control circuit that controls the gain of the amplifier 4; 8;
is the predetermined gain value to be set in the amplifier 4 for each storage medium,
In other words, the standard gain is 7? A storage section 9 that can be folded/read from a host controller is a storage medium, that is, a magnetic tape.

In the above configuration, the storage medium 9 is attached to the magnetic storage device.
When the storage medium 9 is attached, a DGC signal is read and viewed from a predetermined area at the beginning of the storage medium 9 prior to data writing/reading.

At this time, the control circuit 6 is amplified by the amplifier 4,
The gain of the amplifier 4 is set via the gain control circuit 7 so that the output level for the DGC signal detected by the 89 circuit 3 becomes a constant 1 [(hereinafter referred to as standard gain output level) of Pfr. - The gain set by the gain control circuit 7 for the amplifier 4 in this way is the standard gain, and the control circuit 6 stores the standard gain in the storage section 8 and rereads it in the error recovery procedure. except that the gain of amplifier 4 is set to the standard gain.

When a reading error is detected while reading data i17, as part of the recovery error recovery scheme, the part where the reading error occurred, for example, a large-capacity magnetic field; At this time, the gain control circuit 7 adjusts the gain of the amplifier 4 according to instructions from the host controller. Change the standard gain to a larger or smaller value.

When the re-reading is completed, the host controller 1 sets the standard gain stored in the storage unit 8 to the amplifier 4, and
The output level is restored to the standard readout output level before the delta pin. A similar effect can be obtained even if the control circuit 6 sets the standard gain stored in i1 in the storage section 8 at the end of the rereading process.

(2) As described in detail, the present invention allows the standard gain to be set in the amplifier to be set in the magnetic register 1. # Since it is stored on the device side, the amplifier gain can be reliably restored to the standard original gain after rereading as part of the pick-up error recovery procedure.

In addition, even when reading a certain section of the storage medium with the gain of the amplifier raised in anticipation of the occurrence of a reading error υ, the gain of the amplifier can be reliably restored to the original standard gain. can do.

[Brief explanation of the drawing]

The figure shows a block diagram of an embodiment of the present invention, in which 3 is a reading circuit, 4 is an amplifier, 6 is a control circuit, 7 is a gain control circuit, and 8
is a storage unit, and 9 is a storage medium.

Claims (1)

[Claims] a variable gain amplifier that uses a magnetic recording medium as a storage medium and amplifies read multiple signals obtained from the storage medium;
setting the gain of the amplifier to a predetermined value for each storage medium;
and means for changing the gain of the amplifier during re-reading after a read error recovery process, the magnetic storage device comprising: a means for changing the gain of the amplifier during re-reading after a read error recovery process; 1. A magnetic storage device, comprising: a storage section for storing a gain value; and after the error recovery process is completed, the gain value is reset to a predetermined gain value stored in the storage section.