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Introduction of Sequential Circuits The combinational circuits have set of outputs, which depends only on the present combination of inputs. Below is the block diagram of the synchronous logic circuit. The sequential circuit is a special type of circuit that has a series of inputs and outputs. The outputs of the sequential circuits depend on both the combination of present inputs and previous outputs. The previous output is treated as the present state. So, the sequential circuit contains the combinational circuit and its memory storage elements. A sequential circuit doesn't need to always contain a combinational circuit. So, the sequential circuit can contain only the memory element. Types of Sequential Circuits Asynchronous sequential circuits The clock signals are not used by the  Asynchronous sequential circuits . The asynchronous circuit is operated through the pulses. So, the changes in the input can change the state of the circuit. The asynchronous circuits do not us...

De-Multiplexer  A De-multiplexer is a combinational circuit that has only 1 input line and 2 N  output lines. Simply, the multiplexer is a single-input and multi-output combinational circuit. The information is received from the single input lines and directed to the output line. On the basis of the values of the selection lines, the input will be connected to one of these outputs. De-multiplexer is opposite to the multiplexer. Unlike encoder and decoder, there are n selection lines and 2 n  outputs. So, there is a total of 2 n  possible combinations of inputs. De-multiplexer is also treated as  De-mux . There are various types of De-multiplexer which are as follows: 1×2 De-multiplexer: In the 1 to 2 De-multiplexer, there are only two outputs, i.e., Y 0 , and Y 1 , 1 selection lines, i.e., S 0 , and single input, i.e., A. On the basis of the selection value, the input will be connected to one of the outputs. The block diagram and the truth table of the 1...

Multiplexer A multiplexer is a combinational circuit that has 2 n  input lines and a single output line. Simply, the multiplexer is a multi-input and single-output combinational circuit. The binary information is received from the input lines and directed to the output line. On the basis of the values of the selection lines, one of these data inputs will be connected to the output. Unlike encoder and decoder, there are n selection lines and 2 n  input lines. So, there is a total of 2 N  possible combinations of inputs. A multiplexer is also treated as  Mux . There are various types of the multiplexer which are as follows: 2×1 Multiplexer: In 2×1 multiplexer, there are only two inputs, i.e., A 0  and A 1 , 1 selection line, i.e., S 0  and single outputs, i.e., Y. On the basis of the combination of inputs which are present at the selection line S 0 , one of these 2 inputs will be connected to the output. The block diagram and the truth table of the ...

Encoders The combinational circuits that change the binary information into N output lines are known as  Encoders . The binary information is passed in the form of 2 N  input lines. The output lines define the N-bit code for the binary information. In simple words, the  Encoder  performs the reverse operation of the  Decoder . At a time, only one input line is activated for simplicity. The produced N-bit output code is equivalent to the binary information There are various types of encoders which are as follows: 4 to 2 line Encoder: In 4 to 2 line encoder, there are total of four inputs, i.e., Y 0 , Y 1 , Y 2 , and Y 3 , and two outputs, i.e., A 0  and A 1 . In 4-input lines, one input-line is set to true at a time to get the respective binary code in the output side. Below are the block diagram and the truth table of the 4 to 2 line encoder. Block Diagram:                          ...