SU1481735A2 - Data input device - Google Patents

Abstract

The invention relates to automation and computing and can be used to manually enter information into processing devices. The device for entering information contains a keyboard 1, made in the form of switching, containing movable normally closed and normally open contacts, multiplexer 2, element NO 3, element OR 4, RS flip-flop 5, first element AND 6, pulse generator 7, first counter 8 , output 9 of the device code strobe, output 10 of the group of device code bits, the element OR NOT 11, the second element 12, the second counter 13 and the comparison element 14. The invention improves the speed of the device by polling different keyboard keys with different frequencies. 1 il.

Description

The invention relates to automation · and computer technology, can be used to manually enter information into processing devices and is an improvement of the known device according to ed. St. No. 11 12358.

The aim of the invention is to improve the performance of the device.

The drawing shows a structural diagram of the device.

The device for inputting information includes a keyboard 1 made in the form of switching elements containing movable normally closed and 15 normal open contacts, · multiplexer 2, element NOT 3, element OR 4, RS-trigger 5, first element And 6, 7 pulse generator, the first counter 8, the output 9 of the strobe of the device code 20, the output 10 of the group of bits of the device code, the element OR NOT 11, the second element 12, the second counter 13 and the comparison element 14.

The device operates as follows 25.

In the initial state, when none of the keys of the keyboard 1 is pressed, all 30 selectable inputs of the multiplexer 2 have logical 30, 0 ^p , its output is logical 1, the output of element NOT 3 is logical 0, which keeps RS- on the direct output trigger 5 logical 1 ”, allowing the passage of clock pulses from the output of the generator 7 pulses through the first element And 6 to the input of the first counter 8, the output of which appears a sequence of ^2nd codes. ₄₀

When the first counter 8 is set to zero, a logical ”1 is formed at the output of the OR-NOT 11 element, allowing the passage of one clock pulse to the counting input 45 of the second counter 13, increasing its content by one. When the equality of the codes in the first 8 and second 13 counters is reached, at the output of the comparison element 14, a level is formed that resets the contents of the first counter 8, while the contents of the second 13 counters are increased by one. In this case, the first counter 8 generates at its output a sequence of 55 codes, the upper boundary of which with each operation of the comparison element 14 increases by one, and so on until it is full.

Thus, in the device for inputting information, key scanning is implemented according to the selective principle by constantly expanding the polling area from minimum to maximum, then abruptly returning to a minimum, etc. This allows you to organize their more frequent polling and vice versa, by connecting the most frequently pressed keys accordingly, which increases the speed of the device as a whole.

When you press any key of the keyboard 1 on the corresponding selectable input of the multiplexer 2 is fed logical 1.

At the time when the code corresponding to the number _{of the} pressed key is generated at the output of the first binary counter 8, a logical 0 appears at the output of the multiplexer 2, 'and a logical 1 appears at the output of the element NOT 3, which does not change the state of the RS trigger 5. At this phase, the chatter effect it does not affect the operation of the device, since a code strobe is not formed at output 9, which is a sign of a stake at the output of 10 bits of code. When the moving contact reaches the normally open contact of the key at the second input of the OR 4 element, logical 0 will appear. When the first O or 4 input of the logical O appears from the output of multiplexer 2, when the output of the first counter 8 is the code _? corresponding to the dial of the pressed key, a logical 0 will appear at the output of the OR 4 element, which will set logical 0 at the direct output of the RS flip-flop 5 and a logical “1” at the inverse output. Logical 0 from the direct output of the RS trigger 5 will prohibit the passage of clock pulses from the output of the generator 7 through the first element 6 to the input of the first counter 8. Logical 1 at the inverse output of the RS flip-flop 5 goes to the output 9 of the code gate and allows the output of 10 bits of the code to be polled. The chattering effect of the contacts of the keyboard keys in this case does not affect the state of the outputs of the RS-trigger 5 does not change.

When the movable contact returns to the normally closed contact of the keyboard key 1, the appearing logical Г * at the output of the multiplexer '1481735

2, and therefore, logical O at the output of the element NOT 3 (at the S-input of the RS-trigger 5), sets the circuit to its original state.

Claims (1)

Claim A device for entering information by ed. St. No. 1112358, which requires that, in order to improve performance, an OR-NOT element, a second AND element, a second counter and a comparison element, the inputs of the first and second groups of which are connected respectively to outputs $ of the first and second counters, the counting input of the second counter is connected to the output of the second element And, the first input of which is connected to the output of the pulse generator, and the second to 10 by the output of an OR-NOT element, the inputs of which are connected to the outputs of the first counter, the reset input of which is connected to the output of the comparison element.