JPH011104A - Magnetic recording/reproducing device and data recording control device applied to the device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Objective of the Invention (Field of Industrial Application) The present invention relates to a data recording control device for a magnetic recording/reproducing device, which is a floppy disk device.

(Prior Art) Conventionally, in floppy disk drives, a tunnel erase type head is known as a magnetic head for reading/writing data on a magnetic recording medium (disk). In a tunnel erase magnetic head, the seventh
As shown in the figure, in the disk running direction (arrow A), the erase gap 11 is the read/write gap 1.
It is placed at a position temporally delayed from 0. Therefore, when data is recorded on a disk by a tunnel erase magnetic head, the erase is delayed in time with respect to the timing of the write gate signal (WGI in Figure 6) that determines the timing of the recording operation. Gate signal E is output. Depending on the timing of this erase gate signal E, the erase gap 11 erases the areas at both ends between each track by a certain width. With this, it is possible to prevent crosstalk from occurring when reproducing data after recording it, and as a result, it is possible to ensure compatibility between devices.

Here, the write gate signal and erase gate signal are
Generated by the disk controller (FDC). F
As shown in FIG. 6, the DC outputs a write gate signal WGI that becomes active from a sync field in, for example, a disc track format. When this write gate signal WGI is output from the FDC, a disk drive (FDD) having a tunnel erase type magnetic head drives and controls the magnetic head so as to start recording data from the sync field of the disk. Become. As shown in Figure 6, the sink field usually includes an ID field and data (D
ata) is provided at the beginning of the field. Data “00” is recorded in the sink field. F
In a DD read operation, equally spaced read pulses are generated from the sync field, and these read pulses are used, for example, as a synchronization signal for a PLL circuit necessary for a data reproduction operation.

Incidentally, in recent years, high-density recording FDDs and disks have been developed, and efforts are being made to increase storage capacity. A disk used for high-density recording is a recording medium coated with a magnetic material such as barium ferrite, and the coating film is relatively thick. When performing high-density recording (for example, storage capacity is 4 megabytes) on such a high-density recording disk, the recording wavelength is becomes shorter. In order to reproduce data with a short recording wavelength, it is necessary to reduce the read/write gap length (circumferential spacing between tracks) of the magnetic head. on the other hand,
In the magnetic recording operation of the magnetic head, the residual magnetization range (recording magnetic field) in the thickness direction of the magnetic film of the disk is determined according to the read/write gap length.

Therefore, when the read/write gap length is shortened in accordance with the high-density recording mode, it is necessary to reduce the thickness of the magnetic film of the disk to, for example, about 1/4 of the recording wavelength. This is because in the data recording operation, new data is recorded on top of previously recorded data. In this case, the previous data needs to be completely erased, but if the magnetic film of the disk is thick, the recording magnetic field for the previous data is deep, so the read/write gap length corresponding to the high-density recording mode is insufficient. A situation occurs in which data remains. This data remaining without being erased causes crosstalk during data reproduction. On the other hand, it is extremely difficult to make the magnetic film of the disk thinner in terms of manufacturing. As a result, when a tunnel erase type magnetic head is used in a high-density recording mode, there is a drawback that override characteristics in data recording operation deteriorate.

In order to eliminate these drawbacks, a magnetic head of a pre-wide erase type has been proposed. As shown in FIG. 8, this type of magnetic head is a head in which the erase gap 12 is placed at a position ahead of the read/write gap IO in the disk running direction (arrow A). With such a head, before data is recorded using the read/write gap 10, the recording area of the track is widened by the preceding erase gap 12. Therefore, even if the gap length of the read/write gap 10 is shortened according to the high-density recording mode, the previous data can be completely erased in advance during data recording, so good override characteristics can be ensured. Can be done.

By the way, in the advance wide erase method, the timings of read/write and erase operations are controlled to be simultaneous. Therefore, in the data recording operation, the write gate signal and the erase gate signal are output at the same timing.

In an FDD using such a magnetic head of the advanced wide erase method, as shown in FIG.
When data is recorded using this method, the following problems arise. That is, as shown in FIG. 8, the distance between the read/write gap lO and the erase gap 12 is i! lI
They are arranged at intervals of X. Furthermore, since the read/write and erase timings are the same, in the relationship between the relative speed V and distance X between the head and the disk,
The time Δ at which ΔT −x / v J occurs when recording data
An area corresponding to T that is not erased occurs in the sink field. Further, a region shown in FIG. 6 that remains erased by Gap 3 mil 3 field is generated.

In particular, the synchronized field uses the PLL during data playback.
This is an area for reading the synchronization signal of the circuit. Therefore, if the override characteristics are deteriorated without being erased, the S/O of the area that will not be erased during data reproduction
The N ratio deteriorates, and the PL for the reproduced signal from the magnetic head
There is a drawback that the tracking performance of the L circuit is degraded.

(Problems to be Solved by the Invention) When a write gate signal in the tunnel erase method is used during a data recording operation in an FDD using a magnetic head of the advanced wide erase method as a high-density recording mode, for example, Override characteristics for syntafields deteriorate. On the other hand, if a dedicated FDC for the advance wide erase method is prepared, there is a problem that compatibility with the conventional tunnel erase method is lost.

An object of the present invention is to be compatible with both devices using tunnel erase type magnetic heads and advanced wide erase type magnetic heads, and to always maintain compatibility with devices using magnetic heads of tunnel erase type and advanced wide erase type, without causing a situation where override characteristics deteriorate during data recording operation. An object of the present invention is to provide a data recording control device for a magnetic recording/reproducing device that can reliably read/write data.

[Structure of the Invention] (Means and Effects for Solving the Problems) The present invention provides a mode signal output means for outputting a mode signal specifying either the advanced wide erase method or the tunnel erase method, and a mode signal output means for outputting a mode signal specifying either the advanced wide erase method or the tunnel erase method, and a method for outputting data according to the mode. This data recording control device includes a write gate signal output means for outputting a write gate signal during a recording operation. The write gate signal output means outputs a first write gate signal corresponding to the magnetic head of the tunnel erase method, and also outputs an erase gap and a read signal in the magnetic head of the preceding wide erase method in response to the magnetic head of the preceding wide erase method. / This is a circuit that outputs a second write gate signal determined based on the distance between the write gaps. Also,
The present invention is a data recording control device that includes mode selection means for selecting either advance wide erase mode or tunnel erase mode based on a command output from a host system, and write gate signal output means.

With this configuration, in the case of the tunnel erase mode, data recording is controlled by the first write gate signal so as to start from, for example, a sync field. Further, in the case of the advance wide erase mode, data recording is controlled by the second write gate signal so that data recording starts before the sync field, for example. This makes it possible to reliably prevent a situation in which override characteristics in a data recording operation are deteriorated, for example, with respect to a sync field, regardless of the method.

(Example) The present invention will be described in detail below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of a floppy disk system according to a first embodiment of the present invention. In Figure 1,
A disk controller (FDC) 20 inputs and outputs each Pr11aJ control signal and data necessary for read/write operations to and from a disk drive (FDD) 21 under the control of a host computer (CPU) not shown.

During a write operation, the FDC 20 outputs a write gate signal WG and write data WD that determine write timing to the FDD 21. The write data WD is transferred from the CPU to the FDC20. The write gate signal WG is output from the selector 22 provided in the FDC20. The selector 22 selects either the write gate signal WG1 or WO2 according to the mode signal M transferred from the FDD 21 and outputs the write gate signal WG. The write gate signals WG1 and WO2 are respectively FDC2
It is output from each write gate signal generation circuit provided at 0.

The FDD 21 includes a disk drive mechanism, a magnetic head drive mechanism, and a control circuit that controls the operation of each drive mechanism. The FDD 21 includes a mode output circuit 23 that outputs a mode signal M depending on the type of magnetic head. The mode output circuit 23 outputs, for example, a high level (logical level "H") mode signal M if the magnetic head is a tunnel erase method, and outputs a low level (logical level "L") mode signal M if the magnetic head is a pre-wide erase method. ) mode signal M
Output.

FIG. 2 is a block diagram specifically showing the configuration of FIG. 1. As shown in FIG. 2, the FDD 21 includes an FDD 21a having a pre-wide erase type magnetic head (hereinafter referred to as the pre-erase head) 24 and a tunnel erase type magnetic head (hereinafter referred to as the tunnel erase head). There is an FDD 21b having 25. Each F
D D21a and 21b are mode output circuits 2, respectively.
Complies with 3a and 23b. Also, FDC20
is equipped with a write data output circuit 26, and a mode signal M output from each mode output circuit 23a, 23b.
Accordingly, necessary write data W and D (WDI, WD2) are output to each FDD 21a and 21b.

Although not shown, the FDC 20 receives an erase gate signal E necessary for the erase operation of each erase head of the advance erase head 24 and the tunnel erase head 25.
It is equipped with a circuit that outputs.

Next, the operation of the first embodiment will be explained. First, the CPU outputs a drive select signal to enable the tunnel erase type FDD 21b. F
The mode output circuit 23b of the DDC 21b outputs, for example, a high-level mode signal M to the FDC20.

The selector 22 of the FDC 20 receives a high level mode signal M.
Accordingly, the write gate signal WG1 is selected and outputted to the FDD 21b as the write gate signal WG.

Further, the write data output circuit 26 outputs write data WD1 as shown in FIG. 3 in response to the mode signal M.
Output to D 21b. As a result, the tunnel erase head 25 of the FDD 21b starts recording data on the disk that is rotationally driven by the disk drive mechanism of the FDD 21b, in accordance with the timing of the write gate signal WGI. In this case, the recording magnetic field from the read/write gap IO of the tunnel erase head 25 performs a recording operation according to the write data WDI. That is, as shown in FIG.
In accordance with the timing of G1, recording of data WDI is started from a synter field set on a track of the disk. The tunnel erase head 25 writes "oo" to the sync field and writes a predetermined rDATAJ to the data field during the output period of the write gate signal WG1.

At this time, both end areas of the track are erased by the erase magnetic field of the erase gap 11 of the tunnel erase head 25. This erase operation is executed at a timing corresponding to the erase gate signal E shown in FIG. In the tunnel erase method, as shown in FIG. 7, the erase gap [1] is located at a position temporally delayed from the read/write gap 10. Therefore, as shown in FIG. 3, the erase gate signal E is output with a delay of the delay time ΔT.

Next, the drive select signal from the CPU makes the advance wide erase type FDD'21a operable. The mode output circuit 23a of the FDC 21a outputs, for example, a low level mode 4M to the FDC20. The selector 22 of the FDC 20 selects the write gate signal WG2 in response to the low-level mode signal M and outputs it as the write gate signal WG to the FDD 21a. Further, the write data output circuit 26 outputs write data WD2 as shown in FIG.
Output to D D 21a. As a result, FDD2. l
The advance erase head 24 of a receives the write gate signal WG2.
In accordance with the timing, a data recording operation is started on the disk being rotationally driven by the disk drive mechanism of the FDD 21a.

Here, the write gate signal WG2 is a signal that is outputted earlier than the write gate signal WGI by a time ΔT, as shown in FIG. As shown in FIG. 8, this time ΔT is determined based on the relationship between the distance X between the read/write gap IO and the erase gap 12 and the relative speed V between the head and the disk [ΔT-x/vJ] Ru.

As shown in FIG. 6, the advance erase head 24 starts recording data from a gap (G a p 2), which is a position advanced by a time ΔT from the sync field, in accordance with the timing of the write gate signal WG2. It turns out. That is, during the output period of the write gate signal WG2, according to the write data WD2 shown in FIG.
” and write the specified rDATAJ in the data field.
Write. The gap (G ap 2) is a gap necessary for switching the head from read mode to write mode when rewriting the data field,
Normally, it is fixed at 22 bytes.

At this time, the entire track width is erased prior to the read/write gap 10 by the erase magnetic field of the erase gap 12 of the advance erase head 24. This erase operation is executed at a timing according to the erase gate signal E shown in FIG.

In the advance wide erase method, the erase operation is performed at the same timing as the write operation.

By outputting the tunnel erase head and the write data WD1 in this manner, it is possible to start recording the data WD1 from the sync field of the track, for example. In addition, FDD with advance wide erase method
By outputting the write gate signal WG1 and the write data WD2 with early output timing to the 21a, it is possible to start recording the data WD2 from, for example, the gap (G a p 2) of the track.

Therefore, in any type of FDD, it is possible to reliably perform data recording from the sync field of the track. This makes it possible to prevent, for example, a situation in which the override characteristic in the sync field of the disk deteriorates when data is recorded in the high-density recording mode in the advance wide erase type FDD. Therefore, during data reproduction operation, it is possible to generate read pulses necessary for data reproduction from the sync field and make the PLL circuit reliably follow the reproduction signal from the magnetic head, ensuring reliable data reproduction. It can be realized.

FIG. 5 is a block diagram relating to a second embodiment of the present invention. In the second embodiment, the FDC 20 includes a decoder 27, which decodes a command from the CPU 30 instructing the mode. That is, CPU30
is the selected FDD along with the disk select signal.
outputs a command instructing either the advanced wide erase method or the tunnel erase method. The decoder 27 is
Depending on the decoding result, a high level mode signal M, for example, instructing the tunnel erase method is outputted, as in the first embodiment, and a low level mode signal M, for example, instructing the advanced wide erase method, is outputted.

In the second embodiment, as in the first embodiment, each FDD2
The mode output circuits 23a and 23b provided respectively in 1a and 21b become unnecessary. Note 1. The other configurations and effects are the same as those of the first embodiment, so their explanation will be omitted.

[Effects of the Invention] As detailed above, according to the present invention, in a device using a tunnel erase type magnetic head and a device using a pre-wide erase type magnetic head, it is possible to set appropriate timing for each device mode. A write gate signal can be output. Therefore, when recording data in the high-density recording mode using the advance wide erase method, it is possible to reliably prevent a situation in which, for example, the override characteristics of the sync field of a track deteriorate. Further, even when using the tunnel erase method, the data recording operation can be performed reliably.

As a result, data can be reliably read/written in either the tunnel erase type or the advanced wide erase type FDD.

[Brief explanation of drawings]

FIG. 1 is a block diagram relating to the first embodiment of the present invention, FIG. 2 is a block diagram showing the specific configuration of the same embodiment, and FIGS. 3, 4, and 6 are respectively of the same embodiment. A timing chart for explaining the operation, FIG. 5 is a block diagram of the second embodiment of the present invention, FIG. 7 is a plan view of the tunnel erase type magnetic head, and FIG. 8 is a magnetic head of the advanced wide erase type. FIG. 3 is a plan view of the head. 10... Read/Write gap, 11. 12-0
・Erase gap, 20... Disk controller (FDC), 21... Disk drive (FDD),
22... Selector, 23... Mode output circuit, 26
...Write data output circuit, 27...decoder. Applicant's agent Patent attorney Takehiko Suzue Figure 1 Figure 2 Figure 3

Claims (2)

[Claims] (1) In a data recording control device of a magnetic recording and reproducing device that records and reproduces data on a magnetic recording medium using a magnetic head of the preceding wide erase method or the tunnel erase method, either of the preceding wide erase method or the tunnel erase method. a mode signal output means for outputting a mode signal specifying whether the tunnel erase mode is selected, and a mode signal output means for outputting a mode signal specifying whether the tunnel erase mode is the tunnel erase mode or the tunnel erase mode; A first write gate signal that determines a predetermined timing when recording data is output to the magnetic recording medium, and in the case of the advance wide erase mode, a timing signal is output when recording data on the magnetic recording medium. and write gate signal output means for outputting a second write gate signal determined based on the distance between the erase gap and the read/write gap in the preceding wide erase type magnetic head. A data recording control device for a recording/reproducing device. (2) In a data recording control device of a magnetic recording and reproducing device that records and reproduces data on a magnetic recording medium using a pre-wide erase method or tunnel erase method magnetic head, the a mode selection means for selecting either a pre-wide erase mode or a tunnel erase mode; and when the mode selection means selects the tunnel erase mode, the tunnel erase magnetic head drives the magnetic recording medium; outputs a first write gate signal that determines a predetermined timing for recording data on the magnetic recording medium, and in the case of the advance wide erase mode, the timing for recording data on the magnetic recording medium; write gate signal output means for outputting a second write gate signal determined based on the distance between the erase gap and the read/write gap in the preceding wide erase type magnetic head; and from the write gate signal output means. The first output
write data output means for outputting first write data in synchronization with the write gate signal of the magnet, and outputting second write data in synchronization with the second write gate signal. A data recording control device for a recording/reproducing device.