JP2544327B2 - Magnetic disk controller - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a magnetic disk control device capable of controlling writing / reading of variable length identification information to / from a fixed length data recording medium.

A magnetic disk device used as a large-capacity external storage device of an information processing device is required to perform high-speed and accurate data write / read operation.

There are fixed length data and variable length data in the length of data to be written / read, and it is more realistic to handle the variable length data from the viewpoint of the length of the data actually generated. Moreover, it is desirable in terms of saving storage capacity and simplifying the program.

On the other hand, in terms of hardware configuration, fixed length is simpler and faster, and therefore, it is generally based on the operation of fixed length data. One track of the magnetic disk medium for recording / reproducing such fixed length data is composed of records separated by sector pulses.

This record is, as shown in FIG. 3, an identification section (hereinafter referred to as an ID section) a for identifying the position of a sector and displaying magnetic defect information of the sector, a data section b for recording user data, and an ID section. It is composed of gap parts G1, G2, G3 having a predetermined space before and after the data part b.

Further, the ID part a may have a different number of constituent bytes depending on the interface part with the magnetic disk control device of the magnetic disk device or the magnetic disk control device. Normally, each ID part a is a dedicated interface part or magnetic disk. Only the control device is available.

However, there is a need for realization of a magnetic disk control device that can flexibly cope with the case where the ID parts a having different numbers of bytes are read.

[Problems to be solved by conventional technology and invention]

FIG. 2 is a block diagram showing the configuration of a conventional magnetic disk controller.

Normally, when the magnetic disk control device 1 controls the recording / reproducing operation of data for the magnetic disk device (device) 2, first, the contents of the ID part a of the magnetic disk device (device) 2 is previously stored in a microprocessor (hereinafter referred to as MPU). 4), the contents of the ID buffer unit 5 (that corresponds to the shift register 12) in which the ID information is set are compared, and at the time of coincidence, the data recording or reading operation of the data unit b is performed. Take control.

That is, the ID read by the magnetic disk device (device) 2
The serial read data of the part a is converted into parallel read data by the serial / parallel conversion circuit 7 and sent to one terminal of the data comparison circuit 6. Further, the ID buffer unit 5 sends the stored data to the other terminal of the data comparison circuit 6.

The data content of the ID part a is composed of, for example, 6 bytes, and a part for setting a flag when there is a failure, the ID part a
The data such as the cylinder number where is located and the corresponding head number are recorded.

The data comparison circuit 6 compares the input data and outputs a predetermined signal to the AND circuit 6 if they match. This predetermined signal takes a logical product condition with the ID part signal indicating that the reading of the contents of the ID part a is currently controlled, and the output contents are flip-flop circuits (however, in the JK type flip-flop circuit, Set to 9).

When recording the data transferred from the host computer (not shown) and stored in the data buffer 3, the format control circuit 11 sets the format of the medium in the magnetic disk device 2 to the content set by the MPU 4. When the signal from the JK / FF circuit 9 is input, the recording / reproducing operation of the data in the data section b is controlled while controlling the original determination.

The data buffer 3 also has a function of temporarily storing the data transferred from the magnetic disk device 2 in order to send the data to the host computer (not shown). An error correction code circuit (hereinafter referred to as an ECC circuit) 10 is an EC added to the ID part a and the data part b.
C detects bit error of each data,
It is a circuit to correct.

The ID section a as described above is used for the interface section (not shown) of the magnetic disk device 2 and the magnetic disk control device 1.
The number of bytes configured by is different. On the other hand, since the number of bytes stored in the ID buffer unit 5 is fixed,
If the contents stored in advance in the ID buffer unit 5 and the number of bytes of the ID unit a sent from the magnetic disk device 2 do not match, it cannot be handled.

That is, conventionally, not only the operation (recording / reproducing operation) of the magnetic disk device 2 in which the number of bytes of the ID part a does not match can not be controlled, but, for example, if the shift register 12 of the ID buffer part 8 has eight stages, In order to move the data set in the last stage to the final stage, there is a problem that it takes a lot of processing time such as writing in the ID buffer section 8 eight times each time.

[Means for solving problems]

The present invention is intended to realize a new magnetic disk control device that solves the above-mentioned problems, and the problem is to prepare the data for comparing the contents of the discriminating portion and determine the number of bytes of the data to be used. Buffer means having a function of switching according to the number of bytes of the identification section read from the fixed-length record is provided, and the output of the buffer means is compared with the content of the identification section read from the fixed-length record. This is solved by the magnetic disk control device according to the present invention which controls the magnetic disk device.

[Action]

That is, the ID buffer section is composed of a shift register of a predetermined stage and a multiplexer (hereinafter referred to as MPX) that switches the data output from the shift register, and the MPX is switched according to the designation of the number of ID bytes for format control.
By adjusting the output size of the D buffer unit to the ID unit, it becomes possible to flexibly handle and control various ID unit sizes.

〔Example〕

The gist of the present invention will be specifically described below with reference to the embodiment shown in FIG.

FIG. 1 is a block diagram of a magnetic disk control device showing an embodiment according to the present invention. The same reference numerals denote the same objects throughout the drawings.

It is assumed that the shift register 14 has a number of stages that can accommodate a capacity (for example, 8 bytes) larger than the maximum capacity of various ID sections a (for example, the capacity of the ID section a is 4 bytes, 6 bytes, etc.). Further, the output read of the shift register 14 can take out the output corresponding to the number of bytes corresponding to various ID parts a.

The MPX 13 stores a plurality of output leads from the shift register 14 in the register 15 by the MPU 4, switches them according to the data to be output, selects one output lead and outputs it.

The register 15 stores the number of ID bytes for format control, which is obtained by reading a specific record of the device when the power supply specified by the MPU 4 is turned on. Also, shift register
14 also assumes that the maximum number of ID bytes specified by MPU4 has been initially set.

The data comparison circuit 6 is switched according to the output data of the register 15 and the output data of the MPX13 in which one output lead is selected and the data transferred from the magnetic disk device 2 are serial / serial.
The parallel read data converted by the parallel conversion circuit 7 is compared and the data content is confirmed.

When the comparison contents match, a coincidence signal is output to the AND circuit 8, the condition of the AND with the ID part signal is taken, and the coincidence signal is set in the JK / FF circuit 9. Format control circuit 11 is JK
The signal set in the FF circuit 9 controls the next operation.

When the present invention as described above is carried out, the number of bytes of the ID section a and the number of output bytes of the ID buffer section 5 match,
It is not necessary to perform an extra setting operation to the ID buffer unit 5, so that the processing time of the ID unit a can be shortened.

〔The invention's effect〕

According to the present invention as described above, it is possible to control various ID section sizes with one magnetic disk controller.

[Brief description of drawings]

FIG. 1 is a block diagram of a magnetic disk controller showing an embodiment according to the present invention, FIG. 2 is a block diagram showing a structure of a conventional magnetic disk controller, and FIG. 3 is a block diagram of a record. . In the figure, 1 is a magnetic disk control device, 2 is a magnetic disk device, 3 is a data buffer unit, 4 is an MPU, 5 is an ID buffer unit, 6 is a data comparison circuit, 7 is a serial / parallel conversion circuit, and 8 is a logical product. Reference numeral 9 is a JK / FF circuit, 10 is an ECC circuit, 11 is a format control circuit, 12 and 14 are shift registers, 13 is MPX, and 15 is a register.

Claims (1)

(57) [Claims] 1. A magnetic field having a fixed length record comprising an identification part of a record for identifying the item of data and displaying the property of the data, the data part and the identification part, and a gap part having a predetermined interval between the data parts. After controlling the recording / reproducing operation of the data to the disk device, and further comparing the recording / reproducing operation with the contents of the identification part of the fixed-length record and the contents stored in advance, after confirming that they match. An apparatus for controlling the recording / reproducing operation of data in the data part, wherein the identification part content comparison data is prepared, and the number of bytes of the data to be used is adjusted to the number of bytes of the identification part read from the fixed length record. By providing a buffer means having a function of switching the output, the output of the buffer means is compared with the content of the identification part read from the fixed length record, and it is confirmed that they match. Magnetic disk device characterized by controlling the magnetic disk device.