Sequential Logic Gates
Sequential logic gates are electronic components that can be used to create simple circuits. They are made up of two or more switches that can be turned on or off in sequence, and the output of one gate can be used as the input to the next.
Sequential logic gates are often used to create basic circuits, like AND and OR gates. OR gates are the most common sequential logic gate. They have two inputs that can be connected together to create an output. In OR circuits, one input is always true, and the other is always false, so you can use them to make decisions based on those two values.
A logic gate determines what happens in a digital circuit. These are the basic logic gates that are used to build almost every technology product and are the building block of our technological world.
We need to define what a logic gate is. A logic gate is a switching device that can be ON or OFF depending on the signal that is driving it. If a signal is inputted to it, the logic gate will output a signal that is either a 1 or a 0. It can have multiple inputs. In other words, it can be AND, OR, NAND, NOR, XOR, etc.
Digital systems employ a number of devices that are not classified specifically as logic gates. These devices play a unique role in the operation of a digital system. Such things as Flip-flops, counters, registers, decoders, and memory devices are included in this classification.
We discuss truth tables, logic symbols, and the operational characteristics of these devices so that they may be used more effectively when the need arises.
As a general rule, most of these devices are constructed entirely on IC chips. The operation is based to a large extent on the internal circuit construction of the IC. Very little can be done to alter the operation of these devices other than to modify the input or use its output to influence the operation of a secondary device.
Digital logic circuits are classified into two groups. We have worked with logic circuits that make up one part of this classification. AND. OR, NOT, NAND, and NOR gates are considered to be combinational logic circuits. The other part of this classification deals with sequential logic circuits.
Sequential circuits involve some form of timing in their operation. The timing function permits one or several devices to be actuated at an appropriate time or in an operational sequence. Logic gates are the building blocks of combinational logic circuits. A flip-flop is the basic building block of a sequential logic circuit. This unit of the course deals with some basic flip-flop circuits. In a later unit, we look at how the flip-flop is connected to form counters, shift registers, and some memory devices.