Introduction of the machine counter
The counter is the simplest and basic operation. The counter is the logic circuit to realize this operation. In the digital system, the counter is mainly counting the number of the pulses to realize the function of measuring, counting and controlling. At the same time, it has the function of frequency division, the counter is the basic counting unit and some control. The gate is composed of a series of flip-flops with the function of storage information. These flip-flops are RS flip-flops, T flip-flops, D flip-flops and JK trigger. The counter is widely used in the digital system, such as counting the instruction address in the controller of an electronic computer so as to take out the next instruction in order, remember the addition, the number of subtraction, the count of the pulse in the digital instrument, and so on. The counter can be used to display the working state of the product. Generally speaking, it is used to indicate how many pages of the product have been folded and collated. Its main index lies in the number of counters. There are 3 and 4 bits in common. Obviously, the maximum number of 3 digit counters can be displayed to 999, and the maximum number of 4 digits can be displayed to 9999.