CN102289192A

CN102289192A - Digital stopwatch

Info

Publication number: CN102289192A
Application number: CN2011102428424A
Authority: CN
Inventors: 崔业梅
Original assignee: Individual
Current assignee: Individual
Priority date: 2011-08-23
Filing date: 2011-08-23
Publication date: 2011-12-21

Abstract

The invention discloses a digital stopwatch. The digital stopwatch comprises a counting circuit, a display circuit, a counting control circuit and a key debounce circuit. The counting circuit is used for providing an enable signal for the key debounce circuit. The key debounce circuit is used for sending a counting start signal, a counting stop signal and a counting reset signal to the counting control circuit. The counting control circuit is used for generating a reset pulse and an enable pulse so as to control a timing circuit to start to time, stop timing and reset to time. The display circuit is used for displaying a timing result of the timing circuit. The digital stopwatch related to the invention has the advantages of working stability and reliably of a system, strong anti-interference performance, simple hardware circuits, clear program structure and the like.

Description

A kind of digital stopwatch

Technical field

The present invention relates to a kind of digital stopwatch, specifically belong to the digital circuit technique field.

Background technology

Along with development of electronic technology, electronic technology in the application of every field also more and more widely.People also progressively deepen his understanding, and people have also utilized electronic technology and relevant knowledge to solve some practical problemss.As: the design and fabrication of stopwatch.Stopwatch is a kind of indispensable time set commonly used in the athletic competition, and it is a kind of typical digital circuit.

Stopwatch is a kind of common timing tool, and kind is many.With a kind of digital stopwatch of electronics technical design, can provide the dirigibility that is beyond one's reach of traditional manufacturing technology for the user, can shorten manufacturing time and reduce manufacturing cost, brought huge time benefit and economic benefit, be the leap of electronic technology.Usually the electronic technology of indication is primarily aimed at design of electronic circuits, PCB design and IC design.

Summary of the invention

Technical matters to be solved by this invention is at traditional stopwatch manufacturing technology very flexible, makes low, the defect of high cost of efficient, and a kind of digital stopwatch is provided.

The present invention is for solving the problems of the technologies described above by the following technical solutions:

A kind of digital stopwatch comprises: counting circuit, display circuit, count control circuit, key circuit;

Described counting circuit provides enable signal for key circuit, key circuit sends the beginning count signal, stops count signal, reset count signal to count control circuit, and count control circuit produces respectively that quenching pulse, enabling pulse control counting circuit pick up counting, stop timing, timing resets;

Described display circuit is used to show the timing result of counting circuit.

In the described digital stopwatch, counting circuit is made up of clock, frequency divider, 1/100 second digit counter, 1/10 second digit counter, second counter, minute counter, hour counter.

In the described digital stopwatch, key circuit by reset circuit, open/the power failure road, the button debouncing circuit forms, wherein reset circuit, open/the power failure road is connected with the button debouncing circuit respectively.

In the described digital stopwatch, second counter, minute counter, hour counter comprise a decade counter, a sextuple denotation counter respectively.The present invention adopts above technical scheme, has following technique effect:

The present invention adopts the electronic technology design, has advantages such as system works is reliable and stable, strong anti-interference performance, hardware circuit is simple, program structure is distinct.

Digital stopwatch of the present invention contains the button debouncing circuit simultaneously; Accuracy of timekeeping was greater than 0.01 second, and the longest timing time is 24 hours; Timer energy indication range 0.01 second-23: 59: 59.99, figure place showing is 8; Reset key and rise/stop button the inside dithering process that disappears is arranged.

Description of drawings

Fig. 1 is a digital stopwatch structural drawing of the present invention.

Embodiment

Below in conjunction with accompanying drawing technical scheme of the present invention is described in further detail:

As shown in Figure 1, a kind of digital stopwatch comprises compositions such as counting circuit, display circuit, count control circuit, button debouncing circuit.Counting circuit comprises compositions such as clock, frequency divider, decade counter, sextuple denotation counter again.The button debouncing circuit comprises reset key again, open/stop button and button removes compositions such as shake.

Counting circuit is the main body of stopwatch, and divider circuit obtains count signal with benchmark high frequency frequency division, and reference frequency is high more, and the signal accuracy that obtains behind the frequency division is high more; Sextuple denotation counter and decade counter all are with clear terminal, Enable Pin and carry output; Display circuit is sent in counter output, every group when being respectively ten, the time position, divide ten, divide a position, an individual position, second ten, seconds, 1/10 second position, 1/100 second position; Count control circuit produces quenching pulse and enabling pulse, removes to control decade counter and sextuple denotation counter; System counts also requires to stop when resetting, and promptly quenching pulse will make that also enable signal enters low level when making counter O reset, makes counter stop counting; The button debouncing circuit, reset signal is obtained by reset key, and enable signal obtains by rise/stopping button, and button is pressed to low flat, if will obtain high level pulse, only needs negate to get final product once; Because button is a Mechanical Contact, may the company of being taken as handle down when clicking by many, so internal control circuit is not usually directly sent in the push button signalling pulse, only produce a pulse but make button once press assurance by debouncing circuit.Reset key is pressed, and with output low level, but owing to the shake reason, several shake pulses may occur after key is pressed.If design makes button press lasting 3 clock period of counting of back and just exports a monopulse, and if button is pressed the duration greater than 3 clock period, also only exports a monopulse, so promptly eliminate and to avoid key jitter; It is identical therewith to go to shake the method that obtains enable signal by button.

Claims

1. a digital stopwatch is characterized in that comprising: counting circuit, display circuit, count control circuit, key circuit;

2. digital stopwatch according to claim 1 is characterized in that: described counting circuit is made up of clock, frequency divider, 1/100 second digit counter, 1/10 second digit counter, second counter, minute counter, hour counter.

3. digital stopwatch according to claim 1 is characterized in that: described key circuit by reset circuit, open/the power failure road, the button debouncing circuit forms, wherein reset circuit, open/the power failure road is connected with the button debouncing circuit respectively.

4. digital stopwatch according to claim 2 is characterized in that: counter, minute counter, hour counter comprised a decade counter, a sextuple denotation counter respectively in described second.