What is the working principle of shift registers?

In digital circuits, the circuit used to store binary data or code is called a shift register.

Registers are composed of triggers with storage capabilities. A trigger can store one bit binary code and a register for N bit binary code, which consists of n triggers.

Shift registers have the functions of registering numbers and shifting, that is, they can move the numbers in the registers to the right or to the left in turn under the action of shift stroke. It is a synchronous sequential logic integrated circuit, which is often divided into left shift register, right shift register and bidirectional shift register according to the direction of shift. According to the input-output mode of shift data, it can also be divided into four circuit structures: serial input-serial output, serial input-parallel output, parallel input-serial output and parallel input-parallel output.

There are many kinds of integrated shift registers commonly used, such as 74X164, 74X165, 74X166, 74X595 are all eight-bit one-way shift registers, 74195 are four-bit one-way shift registers, 74194 are four-bit two-way shift registers, 74198 are eight-bit two-way shift registers.

Shift registers not only store data, but also move the data left or right in turn under the influence of clock signals.

The data in the shift register can be moved to the right or left bit by bit under the action of the shift pulse. The data can be input in parallel, output in parallel, input in series, output in series as well as in parallel. Serial input and output in parallel are very flexible and have a wide range of applications.

Shift registers can be used for data operation, data processing, serial-parallel data conversion, as well as various shift register counters, such as ring counters, twist-ring counters, etc.