SU953667A1 - Data retrieval device - Google Patents

Description

The invention relates to memory devices and can be used in devices for sampling and processing data pulses and clock pulses (SR) when reading information from memory devices (memories) of cyclic action, such as magnetic disks.

A device for generating information is known, which contains the elements And, the, Q elements of NOT and one-shot til. The disadvantage of this device is low reliability.

The closest technical solution to the invention is a device for generating information, containing two AND-NOT elements, an inverter and a delay element, the output of which is connected to the first input of the first element-20 that AND-NOT, the second input of which is connected to the output of the inverter and the output is with the first input of the second element NAND and with the first output of the device, the output

The second element is NOT connected to the second output of the device, the device input is connected to the inputs of the delay element and inverter C2.

The disadvantage of the device is a large amount of equipment. In addition, it does not provide for the separation of zeros and ones separately in the SI and separately in the data, which reduces its reliability and limits its scope.

The purpose of the invention is to increase the reliability of the device and expand the scope of its application at the expense of possible. selection of read information.

This goal is achieved by the fact that in a device for sampling information containing AND-NOT elements, the first element is NOT and the delay element, the output of which is connected to the first input of the first AND-NO element, is the second input. which is connected to the output of the first element NOT, and the output to the first input of the second NAND element, the inputs of the delay element and the first element are NOT combined and are the information input of the device, the first and second outputs of which are respectively the outputs of the first and second elements NAND, the output of the first element is NOT connected to the second input of the second NAND element and is the third output of the device. In addition, the device contains a second element NOT, a third, fourth, fifth, and sixth AND-NOT elements and a trigger, the counting input of which is connected to the output of the second AND-NOT element, a single trigger output connected to the first inputs of the third and fourth AND elements - NOT, and zero output - to the first inputs of the fifth and sixth elements NAND, the second inputs of the third and fifth elements NAND are connected to the output of the second element; NOT whose input is connected to the output of the first element NAND, the second inputs of the fourth and sixth elements NAND. The solenoids are connected to the input of the first element NOT; the setup input of the trigger and the outputs of the third, fourth, fifth and sixth elements of the NAND are respectively the installation input of the device and the outputs of the device from the fourth to the seventh. Fig, 1 shows a functional diagram of the proposed device; in fig. 2 - time diagrams that show his work. The device contains (see Fig. 1) AND-NOT elements from the first to the sixth 1-6, the first 7 and second 8 elements are NOT, the delay element 9 and the trigger 10, the information input 11 of the device, the outputs from the first to the seventh 12-18 and device installation input 19, also denotes pulses 20 (see Fig. 2) at the information input of the device, pulses 21 at the first output of the device, a sequence of pulses 22 at the second output of the device, inverse input sequence of pulses 23 at the output of the first element NOT, sequentially ( 1 zero pulses of 2 and single impulses with 25 at the outputs of the third and fourth elements AND –NE, respectively, a sequence of zero 26 and single 27 pulses at the outputs of the fifth and sixth elements AND-NOT, respectively, pulses 28 at the output of the delay element, strobe pulses 29 and 30, respectively, on the forward and inverse trigger outputs. The device operates as follows: In the pulse sequence read from the magnetic disk track, there is service information, which is characteristic code combinations. In order to decipher the service information in separate sections of the input sequence, it becomes necessary to count the number of zeros and ones in both the data and the SI. The device allows, by simple logical operations on the input sequence, to receive pulses at one of its outputs at times, corresponding to zero reading, i.e. the absence of a pulse on the track, and on the other outputs - pulses at time points corresponding to the reading of the unit in both the SI and the data. In addition, a clock sequence is formed in the device, which ensures synchronism of further processing of the read information. The read pulse sequence arriving at the input 11 (see. Fig. 1) of the device (see Fig. 2, diagram 20) passes through the element HE 7 (see Fig. 1) to the output of the device (output of units). With the help of the AND-1 element, the inverse input sequence (see Fig. 2, diagram 23) is compared with the delayed by half of the SI following period on the delay element 9 (see Fig. 1) sequence (see Fig. 2, diagram 28) , and at the output 12 (see Fig. 1) the devices are given pulses of zeros (see Fig. 2, diagram 21). The element AND NOT 2 produces a combination of sequences of zeros (see Fig. 2, chart 21) and units (see Fig. 2, chart 20), while the output 13 (see Fig. 1) of the device receives a clock sequence (see Fig. 2, diagram 22), which has the same configuration when entering the device service information and data of any kind. Using the trigger 10 (see Fig. 1), gating pulses (see Fig. 2, diagram 29 and 30) are formed from the clock sequence, defining the boundaries of the digital positions of the SI and data and allowing the elements

-NON 3 and (see FIG. 1) highlight the nui and units in the data (see fig. 2, diagram 2k and 25), and on the AND-NE elements 5 and 6 {. 1) - zeros and ones in SI (Fig. 2, diagrams 2b and 5

27).

Technical and economic advantages of the proposed device as compared with the known one consist in higher reliability due to reduction of equipment by about 10 times and also in the wider field of application of the device due to the fact that the presence of output pulses at the moments of reading as units, 15 as well as zeros, and separately in the SI and separately in the data, allows simplifying the decoding of the service code combinations when searching for data on a magnetic disk track.

Claims (2)

1.Kagan B.M., Adasko V.I., Pure P.P. Mass storage devices. M., Energie, 1968, pp. 52, 53, fig. 2-16. 2. USSR author's certificate No. 752il66, class G & C 7/00, 1980. (Prototype).