SU1674260A1 - Bubbles reader - Google Patents

Abstract

The invention relates to computing and can be used to read cylindrical magnetic domains. The purpose of the invention is to increase the reliability of reading by increasing the accuracy of setting three levels of amplitude discrimination and processing the data obtained as a result of amplitude discrimination. The device for reading the CMD contains a playback amplifier 1, the first and second comparators 2 and 3, the first data register 4, the third comparator 5, the second and third data registers 6 and 7, the digital-analog conversion unit 8, the processing unit 9, the state register 10 and the element And 11. The accuracy of setting discrimination levels is increased by applying the second and third data registers and the digital-analog conversion block. The subsequent processing of the read data improves the read accuracy. This eliminates the need to reread to detect read errors. 1 il.

Description

one

(21) 4741883/24 (22) 08/01/89 (46) 08/30/91. Bul Ne32

(71) Research Center for Physics and Technology

(72) I.V.Kolchanov, V.M.Vard Nn and L.E.Barkova

(53) 681.327.6 (088.8)

(56) The Bell System Technical Journal. - 1981, v.60, MM, p. 485-500, fig. four.

USSR Author's Certificate No. 1300559, cl. G 11 C 11 / 14,1985.

(54) DEVICE FOR READING CYLINDRICAL MAGNETIC DOMAINS

(57) The invention relates to computing and can be used to read cylindrical magnetic domains. The purpose of the invention is to increase the reliability of reading by increasing the accuracy of setting three levels of amplitude discrimination and processing the data obtained as a result of amplitude discrimination. The device for reading the CMD contains a playback amplifier 1, the first and second comparators 2 and 3, the first data register 4, the third comparator 5, the second and third data registers 6 and 7, the digital-to-analog conversion unit 8, the processing unit 9, the state register 10 and element 11, the accuracy of setting the discrimination levels is increased by using the second and third data registers and the digital-analog conversion unit. The subsequent processing of the read data improves the read accuracy. This eliminates the need to reread to detect read errors. 1 il.

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about

The invention relates to computing and can be used to read cylindrical magnetic domains (CMD).

The purpose of the invention is to increase the reliability of reading by increasing the accuracy of setting three levels of amplitude discrimination and processing the data obtained as a result of amplitude discrimination.

The drawing shows a block diagram of a device for reading a CMD.

The device for reading the CMD contains a playback amplifier 1, the first and second comparators 2 and 3, the first data register 4, the third comparator 5, the second and third data registers 6 and 7, the digital-analog conversion unit 8, the processing unit 9, the state register 10 and element and 11.

Block 8 digital-analog conversion contains digital-to-analog converters 12. 13 and the adder 14.

Processing unit 9 includes a decoder 15 and a group of elements OR 16.

The device works as follows.

During the operation, the following operations are performed:

levels of discrimination are established and formed;

the read signal is amplified;

a readable signal is discriminated;

the resulting discrimination data is recorded in data register 4;

data entered into register 4 is processed;

the processing results (read information and readout errors detected) are output directly or with preliminary memorization in the state register 10 to the information outputs of the device.

Before starting operation, the state register 10 is set to its initial state using a signal input to the initial setup of the device. Then, setting and shaping the levels of discrimination is carried out. For this, data defining the values of the two discrimination levels is entered into the second 6 and third 7 data registers through a group of information inputs of the device on a clock signal coming from its first synchronization input. Further, these data are converted by digital-to-analog converters 12, 13 to voltage levels. In this case, two levels are formed at the outputs of digital-to-analog converters 12, 13, and the third level, which corresponds to the average value of the other two, is formed using the adder 14. After the formation of discrimination levels is completed, the device is ready to read the CMD.

The CMD is read as follows.

The readout signal is amplified by amplification of reproduction 1 and is fed to the first inputs of comparators 2,3,5, the second inputs of which contain levels of discrimination. In comparators 2.3.5, the read signal is discriminated by

5 to three levels. The information obtained as a result of discrimination is entered into the first data register 4.

From the first register 4 data, this information is fed to the first group of information inputs of the register 10

0 state and the inputs of the decoder 15 of the processing unit 9. The decoder 15 generates signals at its outputs that correspond to individual states of the data received at its inputs. These signals are combined by OR on the elements OR 16 and are sent to the device outputs both directly (to the first group of information outputs) and with intermediate fixation in state register 10 (to the second group of information outputs).

The signals generated by the processing unit 9 are divided into three types: the first one refers to the read information, the second one refers to the read error signals,

5 to the third - a signal allowing writing to the state register 10 of the initial information and processed by block 9. In the event that a recording resolution signal is generated, the specified information is entered by the gate.

0 is read by AND 11 into the state register 10. After the information from the state register 10 is read, it is prepared to receive the new data. For this register 10 using

5, the signal arriving from the device setup input is set to the initial state.

Depending on the installed levels of amplitude discrimination and the type of information conversion performed by the processing unit 9, there are several modes of operation of the device.

In the process of reading, discrimination levels can be changed by adjusting their

5 under the parameters of the read signal, or remain constant, assigning them the same or different values. In the case of assigning the same values, the discrimination is performed at the same level, and the readable information is generated by block 9 by means of majority processing of the data recorded in the first data register 4 . In case of assignment of different values, the discrimination is carried out on the upper, middle and lower levels. At the same time, the average level can be set to a single, zero or the value of the read signal lying between them. The latter case is the most preferable option for the majority of possible applications of the device, which consists in setting the upper and lower discrimination levels to a single and zero value of the read signal, respectively.

The functions that the processing unit 9 performs in this case consist, firstly, in issuing readable information, which in the simplest case is determined by the average level of discrimination, secondly, in detecting read errors, which result in as the readable signal from the permissible unit level and zero values, as well as the hardware failures of the device, and, thirdly, the generation of a signal that permits the recording of error data and information from the outputs of the first data register 4 to the register 10. The resolution signal is generated here by combining, by OR, those output signals of the decoder 15, which correspond to unacceptable deviations of the amplitude of the read signal and hardware failure.

The considered processing option allows the device to consider the block of information output from the CMD-microassembly and characterize it as read out reliably if there is no data in the register 10 indicating the occurrence of errors, or as read unreliable in the case of their presence.

Thus, the use of the device allows to increase the reliability of reading. The accuracy of setting discrimination levels is enhanced by the use of the second and third data registers and the digital-analog conversion block. The subsequent processing of the read data improves the read accuracy. Finally, there is no need to re-read to detect read errors.

Claims (2)

1. Device for reading cylindrical magnetic domains, containing a reproduction amplifier, first and second 0 5 0 5 0 0 50 five a comparators and a first data register, and the input of the playback amplifier is a device data input; the first inputs of the first and second comparators are connected to the output of the playback amplifier, characterized in that, in order to increase the reliability of reading by increasing the accuracy of the three levels of amplitude discrimination and processing the resulting amplitude discrimination of data, a third comparator, second and third data registers, a digital-analog conversion unit, a unit are entered into the device processing, the status register and the element And, while the first input of the third comparator is connected to the output of the playback amplifier, the information inputs of the second and third data registers are connected to the group of information inputs of the device, the first synchronization input of which is connected to the synchronization inputs of the second and third data registers, outputs which are connected to the inputs of the digital-analog conversion unit, the first, second and third outputs of which are connected to the second inputs of the first, second and t, respectively Comparators whose outputs are connected to the information inputs of the first data register, the outputs of which are connected to the inputs of the processing unit and the first group of information inputs of the state register, the initial setup input of which is the input of the initial setup of the device, the outputs of the processing unit are connected to the first input of the AND element, with the second group of information inputs of the state register and are the first group of information outputs of the device, the second group of information outputs of which are the outputs the state register, the synchronization input of which is connected to the output of the element I. whose second input and the synchronization input of the first data register are connected to the second synchronization input of the device. 2. The device according to claim 1, characterized in that, in order to increase the accuracy of forming the average discrimination level, the digital-analog conversion unit contains two digital-analog converters and an adder, the output of which is connected to the third output of the digital-analog conversion unit, whose inputs are the inputs of digital-to-analog converters, and the outputs of the first and second digital-analog converters are connected respectively to the first and second inputs of the adder and are 716742608 the first and second outputs of the digital-to-digital block, the encoder and the group of elements OR, the tax conversion outputs of which are outputs of the processing block whose inputs are inputs de3. A device according to claim 1, characterized by an encoder, the outputs of which are connected to the fact that the processing unit contains 5 inputs of a group of OR elements.