SU643971A1 - Device for reading-out information from magnetic domain-based storage units - Google Patents

Description

The proposed device relates to the field of computing.

There are known devices for reading cylindrical magnetic domains (CMD) containing a magnetically uniaxial film with CMD, on which CMD advance channels, a CMD divider, two galvanic and electromagnetic sensors, are included, in bridge circuit 1.

These devices are widely used for reading small diameter CMD (3-6 µm), - they allow to obtain a satisfactory level of the output signal due to multiple (30-100 times) extension of the CMD in a band domain.

However, the known devices have a low noise immunity, since they have a small signal-to-noise ratio when reading the CMD.

The closest known device to the present invention is a CMD reading device containing a magnetically uniaxial film with magnetic domains, on which the main advancement magnet 1X domains are located, the magnetic domain divider, the input and one of the high-resolution

which are associated with the main channel for the advancement of magnetic domains, an auxiliary branched channel for the advancement of magnetic domains, which is magnetically coupled with the main channel of the advanced magnetic domains, galvanomagnetic sensors (2.

However, this device also has insufficient noise immunity, since, despite the use of a polar sign when reading a CMD, the galvanomagnetic sensors in it are essentially located at a considerable distance from each other, which reduces the signal-to-noise ratio.

The purpose of the invention is to improve noise immunity.

This goal is achieved by the fact that the ycfroject contains an additional channel for the advancement of magnetic domains associated with the second output of the magnetic domain divider and the main channel for the advancement of magnetic domains.

The proposed device is intended for use in data storage devices with an organization in which, in a communication channel between information registers and information input / output devices, adjacent information bits during reading are separated by two periods of the control field. Due to the described connection, the information of the main channel of advancement of the CMD (channel of communication) is encoded in such a way that the information unit is converted into the sequence P, and the information zero is converted into the sequence "O. FIG. 1, 2 shows variants of the proposed device. In the device of FIG. 1 on the surface of a magnetically uniaxial film 1 with CMD 2 are placed T, I, V, chevron or disk-shaped ferromagnetic applications 3, which form the paths of the main channel 4 of the promotion of the CMD and the auxiliary branched channel 5 of the promotion of the CMD, logical node 6, domain generator 7, extension element 8 The CMD, the CMD divider 9, the second output of which is connected to the main channel of the CMD advance at point 11 through an additional channel 10 of the advancement of the CMD. The galvanomagnetic sensors 12, 13 are located in the expansion element 8 at a distance equal to the period of the structures advancement. The resistors 14, 15 connected to the sensors 12, 13 in the bridge circuit are outside film 1. The length of the additional channel 10 for advancing the CMD for a period of advance structures is greater than the length of the main channel. The distance from the divider output to the connection point 11. Such a device ( Fig. 1) works as follows. The main channel 4 advances information in the form of the presence or absence of CMD. From the auxiliary branched channel generator 7.a 5 advances information in the form of a sequence "10 that goes to one of the inputs of logical node 6. If domain 2 (information unit) advances on the main channel 4, it is divided into two in the CMD divider 9 A domain, one of which moves further along channel 4, and the other enters the additional channel III of the advancement of the CMD and then at the junction point 1 1 goes to the main channel 4, occupies a place behind the first domain at a distance of one period of the advancement structures of the CMD from it. Thus, the information unit is converted to the sequence "11. By interacting with the sequence of domains "10 in logical node 6 (" deny or "exclusive OR), the sequence of domains" 11 is converted into a sequence "01, which corresponds to an information unit. Passing under sensors 12, 13, the sequence of domains “Ol causes,” “6 outputs of the bridge circuit signal“ 1, for example, of positive polarity. If logic “6” does not receive the sequence “11 (information zero” 00), then the output of logical node 6 will be sent to sensors 12, 13 sequence “10, causing the signal“ b of negative polarity from the output of the bridge circuit. Due to the fact that the sensors 12, 13 are located at a minimum distance from each other, namely, at a distance of the period of advancement structures of the CMD, the noise immunity of the device is significantly increased by minimizing interference due to technological variation of sensors and interference from the control field. FIG. 2 shows a variant of the device for. Sshitshan CMD with increased noise immunity. In this device, the sensors included in pairs 12, 13 are also located relative to each other at a distance of the period of the CMD advance structures, and there is also an analogous additional channel 10 of the CMD progress described above. The difference lies in the fact that from generator 7 enters the logical node b (two elements "ban / repeat or" ban and exclusive OR / AND) domain sequence "11, which in the case of zero (sequence" 00) is basically a channel. from the output of the yugic knot, 1a 6 n |) passes through a pair of 12 series-connected sensors and causes the output of the bridge circuit to double cnrFUhi “O, for example, of negative polarity. If there is a unit (sequence “II) in the main channel 4, the output of the logic node 6 leaves the sequence of domains 11, which passes through a pair of 13 serially connected sensors and causes a double signal“ 1 of positive polarity ”from the output of the bridge circuit. In this case, the device’s robustness is significantly improved by increasing the amplitude of the opposite-polarity signals by two times and thus increasing the signal-to-noise ratio by 4 times compared with the known CMD reading device, which uses the amplitude indication of the readout. Increasing noise immunity, i.e., increasing the sig signal / disturbance ratio, allows either to reduce the degree of stretching of the CMD in the band domain and, therefore, by reducing the sensor length and the area of the chevron expander, to increase the degree of integration of the device; or increase the speed of the device, since the interference increases With an increase in its operating frequency; or increase the allowable percentage of variation in the characteristics of galvanomagnetic sensors, affecting the signal-to-noise ratio, i.e. increase the yield of usable devices on CMD; either by combining several noise-resistant pairs of galvanomagnetic sensors of a CMD into a single bridge circuit (using phase separation of readout signals) to reduce the number of amplifiers of signal readings and to reduce the number of terminals of a solid-state memory module on a CMD, or to increase the reliability of the device by reducing the currents through galvanomagnetic sensors ; or to increase the information reliability of the CMD reader.

Claims (2)

1. Bobek L. and others. “TIIER, No. 8, 1975, t. 63, p. 106 2..A USSR Author's Certificate № G) 2 (Yu17, 27.03.75.