SU1105882A2 - Information input device - Google Patents

Abstract

DEVICE FOR THE INPUT OF INFORMATION on the bus. St. 813398, in order to improve the reliability of the device by eliminating repeated recording strobe when the switching elements are opened, the output of the OR element is connected to the third input of the element I., the output of which is the control output of the device.

Description

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(ffut.f The invention relates to computer technology and can be used in input devices in computers, in terminals, in recorders of information using a keyboard. According to the main bus St. 813398, a device for entering information is known, containing a keyboard, the outputs of which are connected with the information inputs of the register and the OR element, the output of which is connected to the input of the one-vibrator, the output of which is connected to the inputs of the elements NOT and the delays, the outputs of which are connected to the inputs of the element I, the output of which is connected to the control The input of the G1 register. The disadvantage of this device is low reliability, since pressing any key doubles recording information into the register at the beginning of pressing the key and releasing the key. Therefore, distinguish between the first and second gates of writing to the register to avoid issuing a zero register state to the output of the device (since the external device needs to know by whom the gate really gives out information). In this case, the second pulse when you release the key may not be, if it worked when released without a chatter. The purpose of the invention is to increase the reliability of the device by eliminating repeated recording strobe when the switching elements are opened. The goal is achieved by the fact that in the device for inputting information, the output of the element OR is connected to the third input of the element AND, the output of which is the control output of the device. FIG. 1 shows a functional diagram of the device; in fig. 2 temporary diagram of the device. The device contains a keyboard 1, an encoder 2, an element 3 OR, a single-vibration 4, a register 5, a delay element 6, an element 7 NOT, an element 8 AND, information outputs 9, a control output 10. The device operates as follows. In the initial state, when none of the keys of the keyboard 1 is pressed, the output level of the encoder 2 is set to zero, the outputs of element 3 OR, the one-shot 4 and delay element 6 are also zero. At the output of element 7 is NOT the level H, at the output of element 8 and the level O. When you press any key on the keyboard 1 on the output buses of the encoder 2, a parallel binary code appears in the form of unit voltage levels on the corresponding output buses. Due to the chattering of the contacts of the switches of the keyboard 1, these levels have the form of pulses at the moment of switching the contacts (tit Fig. 2a). This signal is fed to the information inputs of the register 5 and through element 3 OR it starts the one-shot 4, which produces a pulse of the level of a logical unit (t - t in Fig. 26), the duration of which is longer than the contact bounce. The pulse from the output of the one-shot 4 through the delay element 6 (t - t of Fig. 2c) is fed to the first input of element 8 And through the element 7 NOT (t - tj of Fig. 2d) to the second input of the element and 8, to the third input of the element And 8 a single signal is output from the output of the element OR 3 (the key pressed). At the output of the element And 8, a pulse delayed by the response time of the one-vibrator (tj - t of Fig. 2e) is formed, which is fed to the control input of register 5 and allows recording of information from the output of the encoder 2 to the register 5 and output 10 of the device to report readiness of the device to issue information. An erroneous entry of information into the register 5 by accidentally pressing the second key on the keyboard 1-prevent is rotated by the presence of level i at the output of element 3 OR, since the one-shot 4 does not start and does not generate a pulse. When the previously pressed key is lowered on the output buses of the encoder 2 and at the output of element 3 OR the signal level is zero, the one-shot 4 does not start, the state of register 5 does not change. If the contact bounce occurs when the key is released, the output of the encoder 2 and the output of element 3 OR a burst of pulses occur (ty in Fig. 2a). A one-shot 4 is triggered and a pulse is generated (t j - t of fig. 26), which is inverted in element 7 of HE (t - t, figure 2d) and delayed on delay element 6 (tb - tg of figure 2c). From the output of the element 8 and the control signal is not generated, due to the fact that its formation is allowed after the inverse signal disappears from the one-shot, but by this time the third output of the circuit 8 receives a zero inhibit signal from element 3 OR, characterized by that key is released. Thus, in spite of the bounce of the contacts of the switches of the keyboard 1, the output of the regi-p 5 generates a code that exists not only in

during nikikati keys, and for all the time to press the next key and replace it.

The proposed device for entering information provides an increase in reliability.

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Claims (1)

DEVICE FOR INPUT INFORMATION by ed. St. No. 813398, characterized in that in order to increase the reliability of the device by eliminating the repeated recording strobe when the switching elements are opened, the output of the OR element is connected to the third input of the And element, the output of which is the control output of the device.