SU1304065A1 - Device for digital magnetic recording-reproducing - Google Patents

Abstract

This invention relates to a magnetic recording technique. The purpose of the invention is to reduce the error of the recording-reproduction result. In the process of writing to the element 9, the clock signals, which are a sequence of pulses, the period of which is equal to the length of the interval of the information bit, are supplied from the master oscillator 5, and also receive information to be recorded via the input bus 11. Element And 9 produces a string of this information with a clock signal. The resulting pulse train is modulo-two summed in an EXCLUSIVE OR 6 element with a clock signal from a master oscillator 5. The result is recorded in block 2. During playback, low-pass filter 1 provides such low-frequency filtering, in which the extremes of the playback result corresponding to the pulse cuts do not give an additional zero intersections that form a binary signal, which is modulo two in the element EXCLUSIVE OR 7 and then goes to the trigger 4, which forms the clock the synchro sequence of pulses arriving at the EXCLUSIVE OR element. 8. The data from the last block receives the mark 12. 1 Il. (WITH

Description

The invention relates to magnetic recording, in particular to devices for digital magnetic under-reproduction.

The purpose of the invention is to reduce the error of the recording-reproduction result.

The drawing shows a device for digital magnetic recording-reproduction.

The device contains a low-pass filter 1 connected by an input to the output of the recording-reproducing unit 2, a zero-crossing detector 3, a trigger 4, a master oscillator 5, the first, second and third elements EXCLUSIVE OR 6-8, the And 9 element and the extremum detector 10.

The first element EXCLUSIVE OR 6 is connected by the output to the input of the recording-playback unit 2 and connected by the first input to the first output of the master oscillator 5. Element I 9 is connected by the first and second inputs to the input information bus 11 and the second output of the master oscillator 5, respectively.

The second element is EXCLUSIVE OR

7 is connected by an output to the synchronization input of trigger 4 and is connected by a first input to the output of the detector 3 zero-intersections connected to the information input of the trigger 4.

The third element is EXCLUSIVE OR

8 is connected by an output to the output information bus 12 and is connected by a first input to the output of trigger 4, which is connected to the output clock 13. An extremum detector 10 is connected by an output to the second inputs of the second and third elements EXCLUSIVE OR 7 and 8 and is connected to the output of the playback-recording unit 2 . The output of the low-pass filter 1 is connected to the input of the 3 zero-crossing detector. The output element And 9 is connected to the second input of the first element EXCLUSIVE OR 6.

Digital magnetic recording-reproduction through the proposed device is carried out as follows.

In the process of recording from the first output of the master oscillator 5 to the first element EXCLUSIVE OR 6, a clock signal is supplied, which is a square wave in which the half-period duration is equal to the length of the information bit interval. From the second output of the master oscillator 5, the sync signal, which is a sequence of pulses, the period of which is equal to the length of the information bit interval, is applied to the element 9.

Element I 9 comes through the input information bar 11 information to be recorded. Element And 9 gates this information with a clock signal from the second output of the master oscillator 5. A sequence of pulses coming from the output of the And 9 element is modulated two in the first element EXCLUSIVE OR 6 with a clock signal from the first output of the master oscillator 5. The result of modulo two, the output from the output of the first element EXCLUSIVE OR 6 is recorded in block 2 of the recording-reproduction on the magnetic recording medium.

In the process of playback from the output of block 2 recording-playback result

0 playback from the magnetic recording medium enters the low pass filter 1 and the extremum detector 10. The latter generates a binary signal, the level of which changes at the moments of the extremes of the playback result.

 Low-pass filter 1 provides such low-pass filtering at which the extremes of the playback result corresponding to pulsed clippings do not give additional zero-intersections.

0 A low-pass filter 1 acts on a zero-crossing 3 detector, which generates a binary signal, the level of which changes at times of zero-crossing playback result.

The binary signals of the zero-crossing detector 3 and the extremum detector 10 are modulo-two summed in the second element EXCLUSIVE OR 7. The result of the modulo-2 summation from the output of the second element EXCLUSIVE OR 7

The trigger goes to trigger 4, which also receives a binary signal from the 3 zero-crossing detector. The trigger 4 generates a clock sync sequence of pulses generated by the main extremes of the playback result, the time shift

which is minimal.

The clock sync sequence of pulses from the output of the trigger 4 is supplied to the output clock 13 and to the third element EXCLUSIVE OR

0 8, to which the binary signal of the extremum detector 10 is also applied. The third element EXCLUSIVE OR 8 generates an information sequence of pulses arriving at the output information bus 12.

five

Claims (1)

Invention Formula A device for digital magnetic recording-reproduction, containing a low-pass filter, connected by an input to the output of a recording-reproducing unit, a zero-crossing detector, a trigger, a master oscillator, input and output information buses, and an output synchronizing bus characterized by that, in order to reduce the error of the playback recording result, the first EXCLUSIVE OR element is inserted into it, connected by the output to the input of the recording-playback unit and connected by the first input to the first output specifying g generator, an element And connected by the first and second inputs respectively to the input information bus and the second output of the master oscillator, the second element EXCLUSIVE OR, connected to the trigger input of the trigger and connected to the trigger input of the trigger, the third input EXCLUSIVE OR, connected an extremum detector connected to the output data bus and connected by a first input to the trigger output connected to the output clock, the extremum detector connected to the second inputs of the second and third elements of the EXCLUSIVE OR and connected to the output of the recording-playback unit, the output of the lower filter The frequencies are connected to the input of the zero-crossing detector, and the output of the AND element is connected to the second input of the first element EXCLUSIVE OR.