KR930004218B1 - Time margin measuring method for magnetic recording apparatus - Google Patents

Abstract

The method measures time margin of a magnetic recording device by calculating the difference between the upper portion and the lower portion of the error occurring when shifting only read data to left and right after delaying real data window and read data by certain time, to improve the reliability of magnetic recording devices. It includes a step time checking stage for delaying the read data by A+ or A- step respectively when the data is all electric or not, a delaying state for delaying read data, and a time-margine calculating stage.

Description

Method of measuring time margin of magnetic recording device

1 is a time margin diagram in a data window with data bit oscillations on read of a magnetic recording apparatus.

2 is a time margin measurement method diagram according to the present invention.

3 is a flow chart of the time margin measuring method according to the present invention.

The present invention relates to a method of measuring time margin of a magnetic recording apparatus for measuring the degree of vibration of data bits of a magnetic recording medium.

In general, magnetic recording devices typically redirect the current flowing through the coil windings of the lead / light head on a magnetic-coated disc to write data bits with the magnetic force generated or to read data bits on the disc in reverse. It is.

Since the data bits on the disk have a very high density, the reliability of the magnetic recording apparatus is deteriorated by the peak shift due to mutual magnetic interference between the data bits and the bit vibration caused by the variation of the rotation of the spindle motor. Therefore, an error is more likely to occur when reading data.

Therefore, in order to manufacture a magnetic recording medium and a magnetic recording drive having a high accuracy over a certain level of error occurrence rate, it is required to provide a time margin measuring means for measuring the degree of beat vibration caused by the peak shift and the spindle motor rotational variation. It is true.

According to the present invention, the upper and lower sides are obtained by delaying the actual data window and the read data by a predetermined time to allow easy time margin measurement, and then shifting only the read data to the left and right to measure the occurrence of an error thereof. The time margin can be calculated by obtaining the difference, which will be described in detail with reference to the accompanying drawings.

First, it can be seen from FIG. 1 that the time margin in the data window with data bit oscillation at read time is schematically illustrated. Subsequently, an arbitrary data bit has a -bit vibration and a + bit vibration, and the time margin Tu and Tc, which is the sum of the upper margin and the lower margin, become the time margin.

The method of the present invention is shown in FIG. 2 to measure the time magic, which delays the actual read data and the data window by a certain time and shifts only the read data left and right step by step in order to measure the occurrence of an error thereof. After determining whether an error has occurred and detecting the upper and lower error occurrence positions, the time interval of the upper and lower error occurrence positions is calculated as a time margin, which will be described in more detail.

3 is a flow chart of the time margin measuring method according to the present invention, in which a cylinder (track) from which time margin is measured is formatted, and electrical data (hereinafter referred to as B6) is written in a data pattern.

Subsequently, one of the sides 0 and 1 of the magnetic recording medium is designated, and the step is set to 160 ns, and the data window and read data are arbitrarily set to the right in the time domain. Delayed by A In this state, 516 bytes are arrayed at a specific address in memory, and all the late data (hereinafter referred to as AA) is written (that is, written as WRITE). 516 bytes of sectors are read and overwritten in the * array in memory. As a result, it is checked whether the data of the * array in memory is B6. STEP = STEP / 2) will be shifted (delayed).

On the other hand, if the * array data in the memory is not B6, the overwrite result is wrong. Therefore, it is regarded as causing an error, and when the read data is delayed upward by A-step (STEP = STEP / 2) and the step is repeated five times. The process of checking whether all the data in the memory is B6 by overwriting the * array of memory by reading the data of one sector of the track written in B6 and writing all the AAs with 512 bytes of * array at a specific address in the memory. It will be repeated.

In the above process, when the data of the array is B6 and the read data is shifted upward by A + steps, if the step is not repeated five times, a data error occurs and the upper side is delayed by A-step. In this case, all the AAs are written with 516 bytes in the array, the data of track 1 sector written in B6 is read, and the data in the memory array is overwritten to check whether all the data in the memory is B6. If the step is repeated five times, the step is set to 160ns, and the data window and read data are shifted by A to the right side of the time domain while 516 bytes are arranged in the memory and all AA is written.

This 516-byte data of sector 1 of the formatted track is read and overwritten into the * array of the memory. As a result, it is checked whether all of the * array data in the memory is B6, and if it is B6, the read data is shifted downward by A-step (STEP = STEP / 2), and the time margin is calculated when the step is repeated five times. To do this, the time margin is output by subtracting the lower side from the upper side. In addition, if the * array data in the memory is not B6 during this process, the overwrite result is wrong. Therefore, the error is considered to be an error and the read data is delayed by A + step (STEP = STEP / 2) and the step is repeated 5 times. The process of writing all the AAs with 512 bytes of * array in the memory until iteration is repeated, reading the data of track 1 sector written in B6, overwriting the * array of memory, and checking whether all the data in the memory is B6. Will be repeated.

In this way, the present invention can easily measure the time margin for grasping the degree of beat vibration caused by peak shift and spindle motor rotational fluctuations in various magnetic recording media such as a prop disk drive, a hard disk drive, and a magnetic recording tape. With reference to this, it is possible to manufacture a magnetic recording medium for minimizing errors.

Claims (1)

Time Margin Formatting the cylinder to be measured and writing it as electrical data, delaying the data window and read data to one time axis after specifying the step time interval, and writing the electrical and late data to the * array at a specific address in memory. A step of reading the electrical data of the formatted cylinder (track) and overwriting the * array of the memory and then checking if the * array data in the memory is all the electric data; and if the affirmative, delaying the read data by A + steps. If the set number of steps is checked, and if it is negative, it is regarded as an error and delayed as much as A-step. If the set number of steps is checked, and if the set number of steps is not checked, the late data is inputted in an array in the memory. When the step repeat count is over, set the step to 160ns and the data window will read the read data right. Lag shift step on the other time axis, write late data into * array on memory, read electrical data from the corresponding sector and overwrite * array of memory to check whether all data with memory * array are late data Calculating positive time margin by subtracting the lower side from the upper side when the step is repeated as many times as the set number of times; A method of measuring time margin of a magnetic recording apparatus, comprising: writing all the late data in an array until memory is reached; and detecting a time margin.