For the use of counters, I believe that many are not strange, counting is one of the simplest basic operations, counters are the logic circuits that implement this kind of operation In the digital system, the counter mainly counts the number of pulses to realize the functions of measurement, counting and control. At the same time, it has a frequency dividing function. The counter is composed of a basic counting unit and some control gates. The counting unit is composed of a counting unit. It consists of a series of triggers with information storage functions, such as RS triggers, T flip-flops, D flip-flops and JK flip-flops.

Counters are widely used in digital systems, such as counting the instruction address in the controller of the computer, in order to sequentially fetch the next instruction, in the operation In the multiplication and division operations, the number of additions and subtractions is recorded, and the counting of pulses is performed in a digital instrument. The counter can be used to display the working status of the product. Generally speaking, it is mainly used to indicate how many copies of the product have been completed. Its main indicator is the number of bits in the counter. Commonly there are 3 and 4 bits. 5 and 6 bits, it is clear that the 3-digit counter can be displayed up to 999, and the maximum of 4 digits can be displayed to 9999.

Categories

1. If the number is increased or decreased according to the counting process, the counter can be divided into an addition counter, a subtraction counter and a reversible counter. The addition is the addition counter, and the decreasing counter is the subtraction counter. The increase or decrease is called the reversible counter.

2. If the trigger in the counter is flipped at the same time, the counter can be divided into synchronous counter and asynchronous counter.

In addition, the counter is often divided into binary counters, decimal counters, etc. according to the counter's count hex.

Action

The most sequential logic circuits used in digital electronics. The counter can be used not only for clock counting, but also for frequency division, timing, generation of beat pulses and pulse sequences, and digital operations. However, the calculation result cannot be displayed, and it is generally displayed through an external LCD or LED screen.

Application

Counter application includes records such as call, SMS, data, etc., and supports the user to choose the date of clearing, and add reminder values according to categories, such as users. You can select any day of the month, or the first day and the last day as the record cycle clear date, and add reminder nodes for the duration of the call, the number of SMS messages, and the number of data traffic.

Counters are used in a wide range of applications, not only for counting, but also for frequency division, timing, and various detection circuits and control circuits.

For the convenience of use, some functions such as asynchronous zero setting, preset number, and hold are added to some single-chip integrated counters, and corresponding settings are set. Control terminal.