SU1529207A1 - Device for input of digital information - Google Patents

Abstract

The invention relates to automation and computing, and is intended for inputting alphanumeric information from a keyboard. The aim of the invention is to increase the reliability of the input information by confirming it and the readiness signal while pressing the keyboard key. The device contains a counter 1, a multiplexer 2, the element And 3, the register 4, the keyboard 5, the element AND-NOT 6, the integrating element 7, two triggers 8.9. 1 il.

Description

ate ts5

WITH

to

The invention relates to automation and computing, and is intended for using alphanumeric information from a keyboard.

The aim of the invention is to increase the reliability of the input information.

The drawing shows a diagram of the device.

The device contains a counter 1, a multiplexer 2, an AND 3 element, a register 4, a keyboard 5, an AND-NOT 6 element, an integrating element 7 consisting of a resistor and a capacitor, the first trigger 8 and the second trigger 9.

The device works as follows.

Non-rectangular pulses arrive at the counting input of counter 1 and control the operation of multiplexer 2. At those moments when none of the keys of keyboard 5 are pressed, the output of multiplexer 2 has an O level. This level blocks, by the second input of the AND 3 element, the passage of pulses to the input of the recording resolution of register 4. At the same time, at the output of the AND – HE 6 element, there is also a zero level, which sets the first trigger 8 into one state. The zero voltage level at the inverse output of the trigger 8 sets to “About the trigger 9.

When any key of the keyboard 5 is pressed and its number corresponds to the binary code, a high level signal appears at the output of the multiplexer 2 at its output. At this moment the contents of the counter-u. A correspond to the address of the pressed key. Changing the codes at the output of counter i occurs cyclically, so the signal at the output of the multiplexer will also appear cyclically while the keyboard key is pressed. A single signal from the output of the pultiplexer 2 and the clock signals are sent to the element 3, at the output of which a write enable signal is generated in the register 4. The write enable signal is generated only at the time of the code corresponding to keyboard pressed 5.

0

five

0

five

0

Three keystrokes of the keyboard 5 at the output of the AND element. NOT would also form a single voltage level, which, with a delay determined by the resistor and capacitor parameters of the integrating element, will set a high level at the output of the trigger 8. This voltage level will overwrite with a trigger pulse 9 and generate a device readiness signal.

Drebsz K.Lavip: K. ;; a1 1Itury claim. This is done by delaying the generation of readiness signals.

Such a construction of the circuit allows using the device with a pulse generator of any arbitrary frequency.

Claims (1)

Invention Formula A device for entering digital information, containing a keyboard, the outputs of which are connected to the information inputs of a multiplexer, whose address inputs are connected to the outputs from the reader, the element AND-HE, the first trigger, characterized in that, in order to increase the reliability of the entered information, an integrating element, a second trigger, an AND element, a register whose information inputs are connected to the counter outputs, the outputs are information outputs of the device, and a clock input is connected to the output of the AND element, first the input of which is connected to the clock input of the counter and is the clock input of the device, the second input of the element I is connected to the output of the multiplexer and the clock input of the second triprer whose output is the output of device readiness, and the information input is connected to the output of the output of the first trigger, the information input of which is connected to the power supply bus of the device, the clock input is connected to the output of the integrating element, the input of which is connected to the output of the unit in "About the first trigger and output of the elem. NTA and - not having inputs connected to the outputs of the keyboard.