SU1062774A1 - Device for magnetic recording digital information - Google Patents

Abstract

A magnetic recording digital information signals modified phase modulation, comprising an input data bus connected to the input of shift register outputs connected to the input of the signals modified phase modulation and an input of the signal predistortion conditions connected to the first input pulse shift unit group input bus clock signals connected to the input of the delay unit —and to one of the inputs of the second group of inputs of the pulsed shift unit, and Four outputs of the delay unit, corresponding to four values of the delay value, are connected to the remaining inputs of the second group of inputs of the pulsed shift unit; a frequency divider whose output is connected to the clock inputs of the shift register and the modified phase modulation signal generator, the output of which is connected to one of the driver's inputs signals of predistortion conditions, as well as a recording unit connected to the output of a pulsed shift unit, characterized in that, in order to improve the accuracy and tightness recordings (L by generating optimal distortions of the same magnitude for the same combinations of three adjacent intervals of the recording signal, the frequency divider input is connected to the second output of the delay unit, and the shift register is made six-bit.

Description

The invention relates to a magnetic information recording technique, in particular to digital magnetic recording devices. A digital recording device is known that contains serially connected input data bus, a five-bit shifter, a converter, a decoder delay unit having three delay values, an assembly circuit, block recorders consisting of sequentially connected binary counter, recording amplifier, magnetic heads and their switches; the shift register output is also connected to the decoder l | . However, this device is characterized by the impossibility of increasing the information capacity due to insufficient recording accuracy due to the small number of predistortion values of the recording signals. The closest to the proposed technical essence and the achieved result is a device of digital magnetic recording of modified phase modulation signals, containing an input information bus connected to the input of a five-bit shift register, outputs connected to the inputs of a modifier of a modulated phase modulation and shaper inputs signals of predistortion conditions, the outputs of which through the buffer register are connected to the first group of inputs of the pulse shift block, the input busbar sync signals connected to the inputs of the delay unit and frequency divider and with one of the inputs of the second group of inputs of the pulsed shift unit, other outputs of the delay unit that correspond to the four values of the delay values are connected to the remaining inputs of the second group of inputs of the pulsed shift unit, and the output of the frequency divider is connected to the synchronizing inputs of the five-bit shift register and the forma- tor of the signals of the modified phase modulation, the output of which is connected to one of the inputs of the conditioner yskazheny, the shift pulse output unit connected to the recording unit 2. This device allows you to increase the accuracy of the recording in comparison with the previous device, since the number of predistortion values is increased to four. A disadvantage of the known device is the impossibility of further improving the accuracy of the recording, since for the same combination of three adjacent intervals of the recording signal, depending on the type of input information sequence, this device generates different values of the predistortion value, one. of which will be at the same time non-optimal. The aim of the invention is to improve the accuracy and density of the recording by generating optimal pre-distortion of the same value for the same combinations of three adjacent intervals of the recording signal. The goal is achieved by the fact that in a device for magnetic recording of digital information with modified phase modulation signals, containing an input information bus connected to the input of the shift register, outputs connected to the inputs of the modified phase modulation signal conditioner and inputs of the predistortion condition signal generator connected to the first group the inputs of the pulse shift unit, the input clock of the sync signals connected to the input of the delay unit and one of the inputs of the second group of inputs to the block pulse shift, with four outputs of the delay unit corresponding to four delay values connected to the remaining inputs of the second group of inputs of the pulse shifting unit, a frequency divider whose output is connected to the clock inputs of the shift register and the former of modulated phase modulation, the output of which is connected with one of the inputs of the predistortion condition signal conditioner, as well as a recording unit connected to the output of the pulsed shift unit, the input of the frequency divider is connected to the second th delay unit output, and a shift register configured shestirazr dnym. FIG. Figure 2 shows a block diagram of the proposed device in FIG. 2 — timing diagrams explaining its operation. The device contains input data bus 1 and input bus 2 clock signals, a six-bit shift register 3, a shaper 4 modified phase modulation signals, a shaper 5 signals of predistortion conditions, a delay block b, a frequency divider 7, a pulse shift block 8 and a write block 9. The input information bus 1 is connected to the input of a six-bit shift register 3, the outputs of modulated phase modulation connected to the inputs of the former 4 and the predisturbation conditioner 5, the outputs of the first are connected to the first

the group of inputs of the block 8 pulse shift. Input bus 2 sync signal. The cable is connected to the input of the delay block b and one of the inputs of the second group of inputs of the pulsed shift block, and the outputs of the delay block are connected to the remaining inputs of this group of inputs. The second output of the delay unit is also connected to the frequency delimiter 7, the output of which is connected to the clock inputs of the six-bit shift register 3 and the former 4 modified phase modulation signals, the output connected to one of the pre-distortion condition signals 5. The output of the pulsed shift block is connected to block 9 of the record.

The operation of the device is as follows.

The input information signals (plot a of FIG. 2) from the bus are connected to the information input of a six-bit shift register. The sync signals (plot 5, figure 2) from the bus 2 arrive at the input of block b of delays and one of the inputs of the second group of inputs of block 8 of pulsed shift.

At the output of the delay unit, the sync signals having four delay values are formed, these delayed clock signals are fed to the remaining inputs of the second group of inputs of block 8, and the delayed clock signal having the second delay value is also fed to the splitter 7 frequency input two, and from its output to synchronization inputs of a six-bit shift register and a modifier of modified phase modulation signals.

From the outputs of the six-bit shift register 3, information signals are in parallel received at the inputs of drivers 4 and 5, in which signals of modified phase modulation and signals of predistortion conditions are produced, respectively. The signals of the conditions of distortion come to the pulsed shift unit, which also receives the sync signals from bus 2 and the outputs of the block 6 delays. In the pulsed shift unit, the timing signals are gated with the predistortion conditions signals, and from the output of this block, the predistortion recording signal (plot g, Fig. 2) goes to the recording unit 9 on the media.

The signals of the predistortion conditions are generated based on the analysis of the durations of three adjacent time intervals T, T2 and Td of the signal of the recording of the modified phase modulation (plot in, figure 2), where T,

Tj and T are, respectively, the previous one, the current and subsequent intervals, and T is the clock interval.

Pre-distortions, in the form of temporal shifts of the fronts of the recording signal relative to their nominal positions in the signal (plot in Fig. 2) are formed in accordance with the table.

With other combinations of the durations of adjacent recording signal intervals (plot g, Fig. 2), no distortion in the signal is formed.

The magnitude of the predistortion & t is less than At2, and is approximately 0.05 T, and dtn is approximately

0.08 T.

The increase in the proposed device the number of bits to six in the shift register allows to eliminate ambiguity in determining

the size of the predistortion that took place in the prototype, where the same combination of 1.5T-1T-1.5T intervals can correspond in one case to the predistortion t, and in the other it.

Obviously, both of these values cannot be optimal simultaneously. The recording signal generated by a known device is shown for comparison on a plot (Fig. 2).

The optimal predistortion value for a combination of T intervals. T, Tj T, and T.J T, as shown by experimental studies, will be the magnitude of it’s predistortion, which is realized in the proposed device.

Connection of the frequency divider input to the output of the aaderj unit,

corresponding to the second value of the delay value, provides a more accurate synchronization, taking into account the propagation delay of the signal in the shift register, the drivers and the pulse unit

a shift, which makes it possible to exclude from the composition of the device the buffer register present in the known device.

The recording accuracy of the proposed device can be increased by. magnitude 4 (& tj, - & t) / T, where T / 4 is the detection window for the signals recorded by the modified phase modulation. :

For the experimentally accepted values of ut 0.05T and itj 0.08T, an increase in the recording accuracy is approximately 13%, which makes it possible to increase the recording density by about 10%, or to increase the reliability of recording information; if the density, leave the records unchanged t t t

t

t

Shift Left Shift Left Shift Right Shift Right

and , o /, f Ml /, f | g, g rrrig, g, 7 rr | g, g, g

Claims (1)

DIGITAL INFORMATION MAGNETIC RECORDING DEVICE by modified phase modulation signals, containing an input information bus connected to the input of the shift register, outputs connected to the inputs of the modified phase modulation signal shaper and the inputs of the signal conditioner of the predistortion conditions, connected to the first group of inputs of the pulse shift signal, the input bus connected to the input of the delay unit and to one of the inputs of the second group of inputs of the pulse shift unit, four the delay block outputs corresponding to the four values of the delay value are connected to the remaining inputs of the second group of inputs of the pulse shift block, a frequency divider whose output is connected to the synchronizing inputs of the shift register and the modified phase modulation signal generator, the output of which is connected to one of the inputs of the signal conditioner of the predistortion conditions , as well as a recording unit connected to the output of the pulse shift unit, characterized in that, in order to increase the accuracy and density of the recording path of the optimal predistortion same size for the same combinations of three adjacent recording waveform intervals, a frequency divider input is connected to the second output of the delay block, and a six-bit shift register is formed. SU 1062 <1 4 ^ ·>