JPS6275903A - Magnetic disk recording device - Google Patents

Abstract

PURPOSE:To decrease the burden at the host side and to shorten the processing time by reserving the changing instruction of the recording surface and executing it after the tunnel erasing is completed. CONSTITUTION:While for a latch circuit 10 such as a D-type FF, an H signal is supplied from an erasing delay circuit 1 to a gate input edge G and the tunnel erasing of the disk is executed, to a data terminal D and an enable terminal OE respectively, a side 1 selecting signal 4 and a selecting signal for enable are supplied, and even then, they are reserved together with the recording surface changing instruction and a side 1 signal 9 supplied to a read/write circuit 2 does not change. When the reserving condition is continued, the erasing is completed and the output of the circuit 1 is inverted to L, the reserving is released and the signal 9 from the circuit 10 is changed in accordance with the recording surface changing instruction. Thus, at the host side, the recording surface changing instruction can be outputted by the free timing, the burden at the host side can be decreased and the processing time can be shortened.

Description

[Detailed description of the invention] 11"l'-1"cy>'I JT1"ゝ"11
The present invention relates to a magnetic disk recording device, and particularly to a magnetic disk recording device that selects a plurality of recording surfaces of a magnetic disk to record information. .

1. Execute tunnel erase in case;) Magnetic Disk Recording 1.1 Apparatus 6. [Prior Art]
Dm%y'< Z 9E**@b2,3 is used. Normally, when a magnetic disk recording device selects a desired track from multiple tracks on the recording surface and performs magnetic recording (re-recording), it performs a so-called tunnel erase, in which both sides of the magnetic track are erased at the same time as the desired recording. It has become. The purpose of performing tunnel erase is to prevent crosstalk between tracks during playback.

In a conventional magnetic disk recording device, recording control was performed by a circuit as shown in FIG.

The reference numeral 20 in FIG. 4 is a connector provided for connecting the magnetic disk recording device to a host device such as a computer. This connector 20
4. Side l select signal for selecting the recording surface of the magnetic disk. A select signal 5 for selecting the disk drive and a write gate signal 6 for controlling writing of a signal input from a data line (not shown) onto the magnetic disk are connected. All of these signals are sent from the host side device, and are all signals that become active at a low level according to the par indicated by 1- in each signal name. Each signal is connected to 5V via a resistor on the magnetic disk recording device side of the connector 20 in order to gain a noise margin.
The 'iIt' source voltage is pulled up to the source voltage. The side 1 select signal 4 is directly connected as a side 1 select signal 9 to a 17941 circuit consisting of an IC circuit for controlling recording and reproduction. Further, by forming a logical product of the select signal 5 and the write gate signal 6 using the AND gate 3, a write gate signal 8 is formed, and this signal is input to the read/write circuit 2.

This is to prohibit writing when the drive is not selected.

Further, the write gate signal 6 is input to an erase delay circuit 1, and the signal delayed for a predetermined period is input to the read/write circuit 2 as an erase signal 7.

This is because the recording/reproducing gap of the head precedes the erase gap, so this is a delay for aligning the recording position and the erase position.

The side l select signal 4 is at a low level when selecting side 1 of the magnetic disk 7, and is at a high level when selecting side 0, and the recording surface of the magnetic disk on which writing is to be performed is selected depending on the state of this signal. Conventionally, control on the host side switches the side 1 select signal 4 when the erase signal 7 is high when performing the side 1 ζ selection.

However, according to the tunnel erase method standard, the erase signal 7 is transmitted through the erase delay circuit 7 as shown in FIG.
is formed by delaying the write gate signal 6 by the time rlIi To (for the reasons stated above)
. The rising edge of the erase signal 7 is similarly delayed by To. Therefore, time T2. If the side L select signal 4 is switched during T3 due to a bug on the system side, the side 11 select signal 9 is switched, and while there is an unerased residue on that side, there is also an erase on a different side than the intended side. There was a risk that the data could be erased. Therefore, in the past, the host side device had to control the switching timing of the write gate signal 6 and side 1 select signal 4 by taking into account the delay time of the erase delay circuit, which increased the burden on the host side. There was a problem that the processing time was extended.

[Means for Solving the Problems] In order to solve the following problems, the present invention provides a magnetic disk that performs tunnel erase when selecting a desired recording surface of a magnetic disk and recording information. In the apparatus, a configuration is adopted which prohibits changing the recording surface of the magnetic disk while performing tunnel erase, stores a recording surface change command during tunnel erase, and provides means for executing this command after the erase is completed.

[Operation 1] According to the configuration described above, even if the host side device inputs a recording surface change command while the magnetic disk recording device is erasing, the host side device is prohibited from changing the recording surface during erasing. This eliminates the need to consider the timing of side selection, reduces the burden on the host side, and eliminates the risk of erasing a recording surface other than the intended one or leaving something unerased.

[Example] Hereinafter, the present invention will be described in detail based on the example shown in the drawings. However, in the following description, the same reference numerals will be given to members that are the same as or correspond to the conventional ones, and detailed explanations thereof will be omitted.

FIG. 1 shows the configuration of a recording control system of a magnetic disk recording device employing the present invention.
The side l select signal 9 input to the 7941 circuit 2 is formed by a latch circuit lO. The latch circuit lO is T
It is composed of TLIC and other D flip-flop amplifiers, JK flip-flop amplifiers, etc., and uses the side select signal 4 as an eta input and the erase signal 7 output from the erase delay circuit 1 as a gate input. Further, a select signal 5 is applied to this latch circuit IO as an enable signal OE.

The latch circuit 10 operates as a positive edge trigger as shown in the truth table of FIG.
Select: Outputs the state of data input by signal 4 as side l select signal 9. When the gate input by the erase signal 7 becomes low level, the previous output state is maintained as it is, as indicated by the symbol Qo in FIG. 2, regardless of the data input. Further, when the enable by the select signal 5 becomes high level, the latch circuit 10 will be connected to the gate and the data input as indicated by the symbol Z in FIG.
It outputs a \\i impedance state as shown in . As shown below, the latch circuit 10 performs tri-state input.

With the configuration described below, the host side device can perform side selection at any timing without considering the erase state. That is, when the tunnel erase is performed twice by the erase signal 7 as shown in the middle part of FIG. 3, the erase signal 7 is at a low level as shown in the upper part of FIG. The level of signal 4 can be changed. For example, as shown by the symbol Xl, the side l select signal 4 is
Even if the data input is switched from a high level state for selecting side l to a low level state for selecting side l, this data input is not outputted by the latch circuit 10 until the next rising edge of the erase signal 7 comes. That is, the side 1 select signal 9 actually input to the read/write circuit 2 switches from the high level indicating side O to the low level indicating side I from the time the erase signal 7 rises to high level. This operation is the same even when the side l select signal 4 is switched from low level to high level as shown by symbol x2.

With the above configuration, the host side device can perform side selection without strictly considering the erase timing, and even if the side select signal is accidentally switched due to a bug etc., the side that is different from the target side will not be detected. The risk of being erased is prevented. Therefore, it is possible to significantly reduce the burden on the host side device compared to the conventional method.

In the following embodiments, a latch circuit such as a TLLIC was used as a means for inhibiting and delaying the side select signal, but this means can of course also be implemented using a gate array or a microprocessor as shown in FIG. It is also possible to configure hardware and software to perform inhibition and delay control corresponding to the truth table.

[Effects] As is clear from the explanation below-1-, according to the present invention,
In a magnetic disk recording device that performs tunnel erase when selecting a desired recording surface of a magnetic disk to record information, it is prohibited to change the recording surface of the magnetic disk during tunnel erase, and the recording surface during tunnel erase is prohibited. Since it has a configuration that retains the change instruction and has a means to execute the recording surface change after the erase bond is completed,
The host side device can switch the side select signal without considering the erase timing, reducing the burden on the host side and shortening processing time. The risk of erasing data and the risk of leaving data unerased are prevented.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of a recording control system of a magnetic disk recording device adopting the present invention, FIG. 2 is a table diagram explaining the operation of the latch circuit shown in FIG. 1, and FIG. 3 is a diagram similar to that shown in FIG. 1. FIG. 4 is a block diagram of the recording control system of a conventional magnetic disk recording device. FIG. 5 is a timing chart showing the operation of the circuit.
This figure is a timing chart diagram showing the operation of the circuit of FIG. 4. ]...Erase delay circuit 2...Read/write circuit 3...AND gate 10...U/N circuit t2
Strawberry lees “Control Me 9 Immi) 1゛ Dried Ihi Forehead Figure 5

Claims (1)

[Claims] In a magnetic disk recording device that performs tunnel erase when selecting a desired recording surface of a magnetic disk to record information, a command to change the recording surface of the magnetic disk that is input during tunnel erase is suspended, and the instruction to change the recording surface of the magnetic disk is suspended after the erase is completed. A magnetic disk recording device characterized by being provided with means for executing this change command.