Important Short Questions Answers: Combinational logic

1. Define combinational logic

When logic gates are connected together to produce a specified output for certain specified combinations of input variables, with no storage involved, the resulting circuit is called combinational logic.

2. Define Half adder and full adder

The logic circuit that performs the addition of two bits is a half adder. The circuit that performs the addition of three bits is a full adder.

3. Define Decoder?

A decoder is a multiple - input multiple output logic circuit that converts coded inputs into coded outputs where the input and output codes are different.

4. What is binary decoder?

A decoder is a combinational circuit that converts binary information from n input lines to a maximum of 2n out puts lines.

5. Define Encoder?

An encoder has 2n input lines and n output lines. In encoder the output lines generate the binary code corresponding to the input value.

6. What is priority Encoder?

A priority encoder is an encoder circuit that includes the priority function. In priority encoder, if 2 or more inputs are equal to 1 at the same time, the input having the highest priority will take precedence.

7. Define multiplexer?

Multiplexer is a digital switch. It allows digital information from several sources to be routed onto a single output line.

8. What do you mean by comparator?

A comparator is a special combinational circuit designed primarily to compare the relative magnitude of two binary numbers.

GLOSSARY TERMS

1.                 Combinational logic-When logic gates are connected together to produce a specified output for certain specified combinations of input variables, with no storage involved, the resulting circuit is called combinational logic.

2.                    Encoder-An encoder has 2n input lines and n output lines. In encoder the output lines generate the binary code corresponding to the input value.

3.                 Decoder- A decoder is a multiple - input multiple output logic circuit that converts coded inputs into coded outputs where the input and output codes are different.

4.                 Multiplexer- Multiplexer is a digital switch. It allows digital information from several sources to be routed onto a single output line.

5.                 Demultiplexer- It allows digital information from single input line to be routed onto a several output line sources.

6.                 Hardware description language (HDL)- hardware description language or HDL is any language from a class of computer languages and/or programming languages for formal description of digital logic and electronic circuits.