Count is one of the simplest basic operations. The counter is the logic circuit that implements this operation. The counter is mainly for the pulse in the digital system. The number is counted to realize the functions of measurement, counting and control. At the same time, there is a frequency dividing function. The counter is composed of a basic counting unit and some control gates. The counting unit is composed of a series of triggers with functions for storing information. These triggers include RS triggers, T flip-flops, D flip-flops, and JK triggers..

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 5 and 6 bits. Obviously, the 5-digit counter can be displayed up to 99999, and the maximum of 6 digits can be displayed to 999999.

Type of counter

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

2. 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.

In addition, there are many different categories, but the most common one is the first category, because this classification can make people at a glance, know What trigger is this counter so that the designer can design the circuit.

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