It has n input and to a maximum m 2n outputs Decoder is identical to a

It has n input and to a maximum m 2n outputs decoder

This preview shows page 44 - 53 out of 53 pages.

A decoder is a combinational circuit. It has n input and to a maximum m = 2n outputs. Decoder is identical to a demultiplexer without any data input. It performs operations which are exactly opposite to those of an encoder. Examples of Decoders are following. Code converters BCD to seven segment decoders Nixie tube decoders Relay actuator Comp Architecture - Digital Computer 44
Image of page 44
Diagram and truth table Comp Architecture - Digital Computer 45
Image of page 45
Encoder Perform the inverse operation of the decoder. An encoder has n number of input lines and m number of output lines. The encoder accepts an n input digital word and converts it into an m bit another digital word. Examples of Encoders are following. Priority encoders Decimal to BCD encoder Octal to binary encoder Hexadecimal to binary encoder Comp Architecture - Digital Computer 46
Image of page 46
SEQUENTIAL CIRCUITS Comp Architecture - Digital Computer 47
Image of page 47
Sequential Circuits The combinational circuit does not use any memory. Hence the previous state of input does not have any effect on the present state of the circuit. But sequential circuit has memory so output can vary based on input. This type of circuits uses previous input, output, clock and a memory element. Comp Architecture - Digital Computer 48
Image of page 48
Comp Architecture - Digital Computer 49
Image of page 49
Flip Flop Flip flop is a sequential circuit which generally samples its inputs and changes its outputs only at particular instants of time and not continuously. Flip flop is said to be edge sensitive or edge triggered rather than being level triggered like latches Comp Architecture - Digital Computer 50
Image of page 50
S-R Flip Flop It is basically S-R latch using NAND gates with an additional enable input. It is also called as level triggered SR-FF. For this circuit in output will take place if and only if the enable input (E) is made active. In short this circuit will operate as an S-R latch if E= 1 but there is no change in the output if E = 0 Comp Architecture - Digital Computer 51
Image of page 51
Comp Architecture - Digital Computer 52
Image of page 52
Truth Table Comp Architecture - Digital Computer 53
Image of page 53

You've reached the end of your free preview.

Want to read all 53 pages?

  • Fall '19
  • Boolean Algebra, Logic gate, Combinational Circuits,  Examples of the digital systems

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern

Stuck? We have tutors online 24/7 who can help you get unstuck.
A+ icon
Ask Expert Tutors You can ask You can ask You can ask (will expire )
Answers in as fast as 15 minutes