SU1020864A1 - Method of recording and checking digital information of magnetic medium - Google Patents

Abstract

WAY OF RECORDING AND CONTROL OF DIGITAL, INFORMATION ON MAGNETIC. MEDIA, consisting in the formation of current drops when recording units of a sequence of information signals from an odd number of bits with the number of units in it greater than the number of zeros, in; forming current drops, when writing zeros of a sequence of information signals from an odd number of bits with the number of zeros in it , a greater number of units, in the formation of current differences in the event of a sync signal, in the formation of the first signal error due to violation of the ratio of single and zero signals of the reproduced sequence of info PHOTO signals, characterized in that, in order to increase the control accuracy, the formation of current drops when recording a sequence of information signals is carried out ahead of the current signal clock over the absence of a sequence of information current signal signals in one of the adjacent periods and with a different delay from the sync and chrosignal current differential, if there are adjacent periods of the current differential in one of the | &) and the absence of another in the next, then - | ishi zeros 1ion GOVERNMENTAL of information signals from an odd number of bits when the number of zeros in it, in greater numbers of units, and forming a second error signal by disturbance of the corresponding values and the time position vos1 E produced noghe signal value m, and the adjacent time position of reproduced signals. OD SP) Take off .i

Description

The invention relates to the accumulation of information, in particular, to methods for recording and monitoring digital information on magnetic media, and can be used in digital information storage devices of computational, measuring, and control systems. There is a known method of recording and monitoring digital information on a magnetic carrier, which includes the formation of current drops when recording units of a sequence of information signals 1. The disadvantage of this method is low control accuracy, since it can only detect faults, with only odd lengths within the reproducible information sequence. There is also known a method of recording and controlling digital information on a magnetic carrier, including the formatting of current drops when recording units of a sequence of information signals and the formation of differences when recording the clock signals f 2. But the accuracy of the control provided by this method is low, because when it is used, only faults of odd length are detected and their localization is not ensured. The closest to the proposed one is a method of recording and monitoring digital information on magnetic media, consisting in forming current currents when recording units of a sequence, information signals from an odd number of bits with the number of units in it more than zeroes, in forming current differences when recording the zeros of a sequence of information signals from an odd number of bits when the number of zeros in it is greater than the number of ones, in the formation of current drops when recording clock signals and in the formation of the first signal error and rare disruption ratio and zero sequence signal reproduced information signals H b However, the known method is insufficient in accuracy of control. as in most cases not pos. it installs faulty bits, and only localizes them up to the number of bits in a sequence; it does not detect part of double faults at all, for example, the disappearance of units in the last and the first bits of two adjacent signal sequences, as well as It corrects up to 75% of single crashes. The purpose of the invention is to improve the accuracy of controlling digital information on magnetic media. This goal is achieved by the fact that according to the method of recording and monitoring digital information on magnetic media, consisting in the formation of current drops when recording units of a sequence of information signals from an odd number of bits when the number of units in it is greater than the number of zeros, in the formation of current drops when writing zeros follow information signals. From an odd number of bits with the number of zeros in it, a greater number of ones, in the formation of current drops when recording clock signals, in the formation of the first error signal due to violation of the ratio of single and zero signals of the reproduced sequence of information signals, the formation of current drops during recording sequences of information signals are carried out ahead of the current differential of the clock signal in the absence of a sequence of information in one of the adjacent periods signals of current differential and if there is a synchronization signal in the other and with a delay from the current differential, if there is a current differential in one of the adjacent periods and if there is no other, then it forms. step differential of current when recording zeroes of a sequence of information signals from an odd number of bits with the number of zeros in it more than one, and form a second error signal because of violation of the value and time position of the reproduced Signal and the time position of adjacent reproduced signals. Figure 1 presents the block diagram of the device that implements the proposed method; 2 shows timing charts explaining the essence of the method. The device contains information input 1, input 2 of playback signals from the carrier, unit 3 for converting the original information sequence, unit 4 for playback. neither, the control unit 5, the write unit 6, the unit 7 for decoding, monitoring and correcting errors, the output 8 of the recording signals on the media and the information output 9 of the device. In the device, one input of the conversion unit 3 of the initial information sequence is connected to the input 1 of the device, the other input to the control unit 5, and the output -. with the input of the recording unit 6, the other input of which is connected to the control unit 5. One input of the playback unit 4 is connected to the input 2 of the device, the second input is connected to the control unit 5 and the output is connected to the 7 decoding, control and error correction unit, the second input of which is also connected to the control unit 5, and the output is connected to the output 9 of the device. Figure 2 shows the following timing diagrams; a - initial information sequence, under the lying records and control; b - the same sequence after a delay of 3 periods, splitting into three bits of information sequences and inventories of those in which the number of zeros is greater than the number of units / in the meaning of inversion signs; g - current drops when recording a clock signal; e - current drops when recording information signals; e - reproduced sync signals, -, g - reproduced information signals {failed bits are conventionally shown by shaded J; 3 - error signals (5 - oaibki signal produced at the place of the missing signal by the presence of two zeros in a sequence of three bits; 52 - an error signal generated at the place of the missing signal due to a mismatch between its value (. Zero) and temporal positions of signals in Adjacent periods); and - correction signals for faulty bits; k - output information sequence. The initial information sequence (Fig. 2a) is fed to the input of the 1-device, and then to the conversion unit 3 of the original sequence, in which the initial sequence is the delayed recording time required for determining the ratio of the number of ones and the zero of a fixed sequence of an odd number of bits (here out of three bits), and invert the sequences with the number of single bits less than the number of zero bits (Figure 26). The formation of differences is carried out in block 6 of the rhinophrosequence. (Fig. 2d) 6 taking into account the signs of inversion (Fig. 2c) and the values of this and adjacent bits. If the number of units in a sequence of three bits is greater than the number zero (FIG. 2B is the first, second, third, and fifth triad), then current drops when recording single signals or even if the clock current peaks are ahead (FIG. 2d is the first differential): if there is no current differential in one of the adjacent periods (for example, prior to this, and in the other (for example, the follower) is present, or with a delay from the current difference of the sync signal (fig.2d - fourth and nine differential drop), if in one of the adjacent periods (for example, preceding deme) there is a current differential, av friend (it doesn’t exist), or simultaneously with a current differential; a sync signal (fig.2d is second, third; fifth, sixth and tenth perestroc), in both adjacent periods of the period or are present or absent. If the number of zeros in a sequence of three bits is greater than the number of ones (fig.2d is the fourth triad), then step-wise current drops are formed when recording zeroes of the sequence of information signals and either ahead of the sync current signal overshoots /, her-, whether in the predestine For this period, there is no current differential, and later it is present, either with a delay from the Sync signal current differential, if there is a current differential in the previous period, and there is no current signal in the subsequent period (Sync signal, fig.2d - eighth ), if in . both of the periods adjacent to this period are either current or absent. From the output 8 of the block 6 recording on magnetic media remember the type of the sync signal and the information signal of the form. During playback, the synchronization and information sequences of the playback signals are amplified in playback unit 4 and in the form of FIGS. 2e and 2g (the faulty signals are shaded) are fed to the unit 7 for decryption, control and error correction. In block 7, the number of current drops (normal or stepwise) in each of the sequences f consisting of three periods is first checked and the first error signal 5 is generated by varying the ratio of single and zero signals of the reproduced sequence of information signals (Figure 2c. Then, the correspondence of the value and temporal position of the reproduced information signal with respect to the reproduced clock signal to the values and temporal position of adjacent reproduced information signals is checked. in case of violation of the correspondence established during the recording, a second error signal Sj is generated (Fig. 2z). Thus, almost any failures are detected. In block 7, the correction of the fail-bits is generated (Fig. 2i) in a sliding interval of Five periods of the error signals 5: and 82 and the values of the reproduced signals in the interval. Thus, the correction signal 1 of the failed fourth time in the sequence of infor ion signals is formed by the mismatch of its (zero) time values the position of the signal of the previous third bit relative to the sync signal (coincidence of the signals in time, which means the same values of bi-). iTOS in the fourth and second bit.}. Correction signal 2 of the faulty nth bit is generated from signal 5 in the second triad and zero. the sixth bit, - the reliability of which is established by matching the time field of the seventh bit and the values of the sixth and eighth bits. The correction signal 3 of the bad ninth bit is formed by the presence of signal 5 in the third triad and the proven values of the eighth and seventh bits. Correction signal 4 of the thirteenth failing bit is generated, the mismatch is its value (zero time position of the previous twelfth bit relative to the sync signal (coincidence of signals in time, which means identical bit values in the eleventh and thirteenth bits) and additionally by the presence the Sg signal in the fifth triad and the values of the fourteenth (null) and fifteenth (single J bits). As a result, from the output of block 7, the output of the device receives the information sequence 2k, in which corrupted bits are corrected and there are no undetected control failures. Using the proposed method of recording and controlling digital information on a magnetic medium provides increased control accuracy by detecting failures of any multiplicity and correcting up to 100% of single failures, significant. failures (up to 81%), as well as parts of triple and quadruple failures.

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Claims (1)

METHOD OF DIGITAL, MAGNETIC INFORMATION. CARRIER, consisting in the formation of current drops when writing units of a sequence of information signals from an odd number of bits with the number of units in it, more than zeros, in the formation of current drops. When writing zeros of a sequence of information signals from an odd number of bits with a number of zeros in it, more the number of units, in the formation of current drops when recording clock signals, in the formation of the first error signal for violation of the ratio of single and zero signals of the reproduced sequence of information data signals, characterized in that, in order to improve the control accuracy, the formation of current drops when recording a sequence of information signals is carried out ahead of the clock signal drops in the absence of a sequence of information signals of the current drop in one of the adjacent periods, and if there is a delay in the other and from the difference the syn-g current of the hrosignal signal, if there is a drop in current in one of S adjacent periods of the current and if there is no in the other, then a stepwise current drop is formed when recording zeros information signals from an odd number of bits with the number of zeros in it exceeding the number of units, and they form a second error signal for violation of the correspondence of the value and the temporary position of the rep. the generated signal to the values and temporal position of adjacent reproduced signals. I ate hungry entrance Q0 B 4 ^>