Q1: What is a digital counter?
Counting is one of the simplest and most basic operations. In digital logic and computing, a counter is the logic circuit that implements this operation. In digital systems, a counter mainly counts the number of pulses for measurement, counting, control, and other functions. It also has a frequency division function. A digital counter consists of a basic counting unit and some control gates. The counting unit consists of a series of various flip-flops with the function of storing information. These flip-flops include RS flip-flops, T flip-flops, D flip-flops and JK flip-flops. Counters are widely used in digital systems. For example, in the controller of an electronic computer, the next instruction is taken out sequentially by counting the instruction address. The operation unit records the number of additions and subtractions when multiplication and division operations are performed. A counter can be used to indicate the operating status of a product. In general, it is mainly used to indicate how many copies of the product have been folded and sorted. Its main indicator lies in the number of bits of the counter, commonly 3 and 4 bits. Obviously, a 3-digit counter can display up to 999 and a 4-digit counter can display up to 9999.
Q2: How to choose a digital counter?
- The choice of the built-in crystal oscillator.
- The resolution of the digital counter.
- Large screen touch design.
- The counter has more measurement functions.
- Internal crystal oscillator calibration function.
- The communication interface of the counter should be as many as possible.
- Wide measuring range
Q3: Types of counters
- According to whether the flip-flops in the counter are flipped at the same time, the counter can be divided into two types: synchronous counter and asynchronous counter.
- According to the increase and decrease of numbers in the counting process, the counters can be divided into addition counters, subtraction counters, and reversible counters. It is an up counter that keeps increasing with the clock signal, and a down counter that keeps decreasing. A counter that can be incremented or decremented is called a reversible counter.
The most commonly used is the first one because it allows people to know at a glance what triggering method this counter is so that designers can design circuits.
Tips: Digital counter applications in digital system
Counter is a typical sequential logic circuit and also is the most used sequential logic device in digital systems. Using a digital counter to count pulses or conduct fractional frequency can achieve measurement, calculation, timing control and other functions. In addition to the counting function, the counter also has functions such as asynchronous reset, preset parameter, and hold. The preset function is divided into two kinds: synchronous preset and asynchronous preset. The former is controlled by timing pulses, and the latter is not controlled by timing pulses. The hold function is also divided into two types: hold-carry and hold-without-carry. The counter can also be used as a sequential pulse generator.