JPS61156574A - Write/read-out controlling circuit of magnetic disk driving device - Google Patents

Abstract

PURPOSE:To produce stably a high recording density magnetic digital driving device by inputting a digital parameter at every individual head disk assembly, and controlling a pre-shift quantity and a write current at the time of write of information, and a signal amplification degree and a waveform control constant at the time of read-out, at every magnetic head or cylinder. CONSTITUTION:At the time of a write operation, a write data Wd is brought to code conversion to a write pattern Ws by a data modulating circuit 8, brought to delay working for a prescribed time based on a track parameter P by a write pre-shifting circuit 10 and a pre-shift controlling circuit 20, and a pulse Ws is outputted. Subsequently, it is converted to a write current signal Wc by a write current device 30, but a write current value is determined by inputting a write current parameter and a cylinder parameter. On the other hand, a read-out signal Rs from a head selecting write/read-out circuit 4 passes through an amplifier 50, executes a waveform shaping in accordance with a constant of a variable attenuator by a control output based on an equalizer parameter and a cylinder area parameter in the track parameter P in a waveform equalizer 70, and sends out a read-out signal pulse Rc to a data demodulating circuit 9.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a control circuit configuration of a magnetic disk drive device.
In particular, the present invention relates to a write/read control circuit that compensates for variations in magnetic recording characteristics between a plurality of tracks and enables high-density recording.

[Conventional technology]

Conventionally, this type of magnetic disk drive device does not have a means to notify the drive circuit of characteristic variation information for each head disk assembly or for each individual head in a straight manner in an electrical circuit and real time manner, and as a result, writing and The read circuit characteristics are matched to an average head disk assembly or average head characteristics.

[Problem that the invention seeks to solve]

Therefore, in order to guarantee operation against product-to-product variations, the magnetic recording density had to be lower than the maximum performance, or strict specifications were required for disk media and head characteristics. .

The present invention provides an apparatus that solves the above problems.

[Means for solving problems]

The present invention relates to a magnetic disk drive device in which a head disk assembly consisting of at least one information recording disk plate and at least two or more magnetic heads arranged on the disk plate surface is used as a replacement unit. When writing information, the preshift amount and write current can be varied at least for each magnetic head or cylinder. The write/read control circuit is characterized in that it has circuit means capable of variable control of all or more of read signal amplification and waveform control constant during control and information reading.

〔Example〕

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

FIG. 1 is a block circuit diagram of an embodiment that best represents the scope of the present invention. A head disk assembly 1 includes at least disk media 2 arranged concentrically around the same rotation axis.
and a head 3 disposed thereon are essential components, and the head 3 is connected to an external write current generator 3° and a read signal amplifier 50 via a selective write/read circuit 4. . At least the output of an external head address register 6 is input as a control input to the selective write/read circuit 4, and the output of the same head address register 6 is input to the track parameter storage circuit 5. Also, part or all of the output of the cylinder address register 7 is input as another input to the track parameter storage circuit 5. Among the components of the head disk assembly 1 described above, except for the track parameter storage circuit 5, the other elements may be the same as or equivalent to those of the conventional head disk assembly.

Next, as shown in FIG. 1, the components related to the present invention other than the head disk assembly 1 of the magnetic disk drive device include at least a head address register 6 for storing a head address, and a cylinder address register for storing a cylinder address. a register 7; a data modulation circuit 8 which receives write data Wd as an input as a data bus during a write operation and performs code conversion into a write pattern Ws suitable for magnetic recording;
A write preshift circuit 10 which has the output of the data modulation circuit 8 as its input, is also connected to the preshift control circuit 20, and executes a preshift (temporal fine adjustment) operation for each beat of the write pattern. The output Wp of the write preshift circuit 10 is input as a first input, and the write current control circuit 40
A write current generator 30 is also connected to the terminal and outputs a write current signal Wc in accordance with a preshifted write pattern, and also serves as a data bus during a read operation to input a read signal Rs from the selected write/read circuit 4 to the first input, and the increase in intensity control circuit 60
A read signal amplifier 5 is also connected to output the read signal Rp.
0, a waveform etc. 70 which takes the read signal Rp as the first input, is also connected to the pulse shaping control circuit 80, and outputs the read pulse signal Rc, and has the read pulse signal RC as the input, and is connected to the pulse shaping control circuit 80. The output of the track parameter storage circuit 5 is inputted to the data demodulation circuit 9 that demodulates the pattern) Rd, as well as the preshift control circuit 20, write current control circuit 40, increase degree control circuit 60, and pulse shaping control circuit 80, respectively. There is.

The circuit configuration in FIG. 2 is completely the same as the embodiment shown in FIG. , is located on the side of the magnetic disk drive device outside the head disk assembly 1, which means that in this embodiment, the head disk assembly 1 may have the conventional configuration itself.

Next, the configuration of another embodiment shown in FIG. 3 will be explained.

In the embodiment shown in FIG. 3, the circuit functional components are the same as in the example shown in FIG. 1, except that some or all of the outputs of the cylinder address register 7 are connected to different cylinder areas C. That is, according to FIG. 3, the output of the cylinder address register 7 and the cylinder area C are respectively controlled by the preshift control circuit 20, the write current control circuit 40, the amplification gain control circuit 60, and so on. It is also characterized in that it is connected to the pulse shaping control circuit 8o. That is, the difference between the two embodiments is that the parameter variable control based on the difference in cylinder area (address area) is performed in the track parameter storage circuit 5 in the embodiment of FIG. Track parameter P
However, in the embodiment shown in FIG. 3, they are combined in each control circuit.

Next, the input/output signal structure of the track parameter storage circuit 5 shown in FIGS. 1 and 3 will be explained using the example of the structure of the track parameter P shown in FIG. 4. Referring to FIG. 4, the track parameter storage circuit 5 includes at least the head disk assembly 1.
A parameter group (H
AG, HAl, . It is required that it be a thing. The case of outputting the characteristic parameters of the head address selected based on at least the contents of the head address bus h corresponds to the embodiment shown in FIG.

Track parameter storage circuit 5 in the embodiment of FIG.
The configuration requires a structure that can further store and hold the track parameters for each head address described above as a parameter set for each area based on the cylinder area C address, and as shown in FIG. As a parameter, there are 7 Linda areas ($0, #
1,...#N) parameters (HAG, HA
g(1), ..., HA, ring) exists. As shown in the figure, these parameters P are individually set for each controlled circuit or in common, such as a preshift amount, a parameter Pps, a write current parameter Pc, a readout amplification degree, a parameter Pc, and an equalizer parameter Pe. Consists of elements. Next, using Figures 5 to 7, Figure 1~
A more detailed circuit configuration example of each parameter variable control circuit shown in FIG. 3 will be explained.

FIG. 5 shows a more detailed plotter circuit diagram of the write preshift circuit 10 and preshift control circuit 20 in FIGS. 1 to 3. Referring to the figure, write data Wd is modulated into a write code by an encoder/decoder circuit 11,
For preshift processing, the signal passes through a delay circuit 12, is delayed by a predetermined time by a gate circuit 13, and is output as a preshift pulse Ws.

The delay circuit 12 is designed to compensate for the characteristics of the head disk assembly (lackiness,
It is composed of individual delay circuits 12a, 12b, . . . , 12n that cut out all fluctuations such as cylinder area effects.

The gate circuit 13 controls the individual delay circuits 12a, 12b, . . . by gate control from the preshift control circuit 20.
......, 12n as individual gate circuits 13a, 13
b, Gate at .--113n.

The main selection condition for the gate circuit 13 is determined by the delay amount selection bus e given from the encoder/decoder circuit 11 to the preshift control circuit 20, but in the preshift control circuit 20, the selection condition is determined based on the contents of the preshift amount parameter Pp to the cylinder parameter C. It performs a decoding function to finely increase or decrease the delay amount specified by the delay amount selection bus e.

FIG. 6 shows a more detailed block circuit diagram of the write current generator 30 and write current control circuit 40 in FIGS. 1 to 3.

Referring to the figure, the preshift pulse Ws is the write current generator 3.
0 is converted into a write current pattern. At this time, the write current value inputs the write current parameter Pc or the cylinder parameter C, and the decoder 41 that outputs the digital write current value level, and the output of the decoder 41. It is determined by the output level of the input digital-to-analog conversion circuit 42.

FIG. 7 shows more details of the stored information readout system consisting of the readout signal amplifier 50, the boost control circuit 60, the number of waveforms 70, and the pulse shaping control circuit 80 shown in FIGS. 1 to 3. A block circuit diagram is shown. Referring to the figure, the read signal Rs from the head selection write/read circuit 4 is amplified to a predetermined level by an automatic gain adjustment amplifier 51, but at this time, the macroscopic degree of amplification is determined by the track parameter P. Based on the reading amplification parameter Pg or the cylinder area parameter C contained therein, a digital level control amount is given by the decoder circuit 61 as an analog amount by the digital-to-analog conversion circuit 62. The readout signal amplified by the automatic gain adjustment amplifier 51 is passed through the bandpass filter circuit 52 and given to the waveform equalizer 70 as a signal Pp, where it is equalized by the equalizer parameter Pe in the track parameter P or the cylinder area parameter C. Decoder circuit 81 based on
A control output at a digital level is given to the variable attenuator 82, and as a result, the waveform is shaped according to the constant of the variable attenuator 82, and is sent to the data demodulation circuit 9 as a read signal pulse Rc.

〔Effect of the invention〕

As explained above, the present invention focuses on variations in magnetic recording characteristics between individual heads or cylinders, and includes a means for preliminarily testing and evaluating the characteristic values of each product and presenting the results as digital parameters; By using means for detecting digital parameters using hardware and by varying the write control circuit constants and read control circuit constants based on the indicated values of these parameters, it is possible to optimally compensate for variations in characteristics resulting from the combination of heads and disk media. . As a result, magnetic disk drive devices that require high recording density can be stably produced with less influence of variations in characteristics of disk media heads, and errors and the like when reading recorded information can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a block circuit diagram showing a first embodiment of the present invention;
FIG. 2 is a block circuit diagram showing another application example of the first embodiment, FIG. 3 is a block circuit diagram showing a second embodiment of the present invention, and FIG. 4 is a block circuit diagram shown in FIGS. 1 to 3. FIG. 5 is a more detailed block circuit diagram of the write preshift circuit 10 and preshift control circuit 20 shown in FIGS. 1 to 3, and FIG.
A block circuit diagram showing a more detailed circuit example of the write current generator 30 and the write current control circuit 40 shown in FIGS.
FIG. 7 shows the readout signal amplifier 50 shown in FIGS. 1 to 3.
, amplification gain control circuit 60. 7 is a block circuit diagram showing a more detailed example of the circuit configuration of the waveform equal-sided type 70 and the pulse shaping control circuit 80. FIG. 1...Head disk assembly, 2...Disk medium, 3...Head, 4...Head selection writing/continuation circuit, 5... ...Track parameter storage circuit, 6...Head address register, 7...Cylinder address register, 8...
...Data modulation circuit, 9...Data demodulation circuit, 10...Write preshift circuit, 11...
... Encoder/decoder circuit, 12... Delay circuit, 13... Gate circuit, 20-... Preshift control circuit, 30-... Write current generator, 40...
...Write current control circuit, 41...Decoder circuit, 42...-DAC (digital-analog conversion) circuit, 50...Read signal amplifier, 51
・---AGC lead amplifier, 52...Band filter circuit, 6o...Amplification degree control circuit, 6
1...Decoder circuit, 62...DAC
Circuit, 70... Waveform equalizer, 8o...
Pulse shaping control circuit, 81...decoder circuit,
82...variable attenuator,

Claims (1)

[Claims] (1) In a magnetic disk drive device in which a head disk assembly consisting of at least one information recording disk plate and at least two or more magnetic heads arranged on the disk plate surface is a replacement unit, an individual head disk assembly is used. When writing information, the preshift amount and write current can be varied at least for each magnetic head or cylinder. 1. A write/read control circuit comprising circuit means capable of variable control of all or more of read signal amplification and waveform control constant during control and information reading.