Draw the logic circuit of Decimal to BCDencoder, Computer Engineering

Assignment Help:

What is an encoder? Draw the logic circuit of Decimal to BCD encoder and explain its working.

Ans. Encoder: It is a combinational logic circuit which converts alphanumeric characters in Binary codes. It has 2n (or less) input lines and n output lines.  It may be Decimal to Binary or Hexadecimal to Binary or Octal to BCD etc.

Decimal to BCD Encoder:  It has 10 inputs (for decimal numbers 0 to p) and 4 outputs for the BCD number. Therefore this is a 10 line to 4 line encoder. Table (a) shows the decimal digits and the equivalent BCD numbers. By this table, we can get the relationship between decimal digit and BCD bit.  MSB of BCD bit is Y3.  For decimal digits 8 or 9, Y3 = 1. Hence we can write OR expression for Y3 bit as Y3 = 8 + 9

Likewise, Bit Y2 is 1 for decimal digits 4,5,6 and 7. Therefore we can write OR expression

Y2  = 4 + 5 + 6 + 7

Y1  =  2 + 3 + 6 + 7

Yo   = 1 + 3 + 5 + 7 + 9

The logic circuit for the expressions (Y0, Y1, Y2, Y3) is demonstrated in fig. (b). As a High shows on any of input lines the equivalent OR gates provide the BCD output. For example, if decimal input is 8, High shows only on output 3 (and LOW on Y0, Y1 , Y2), hence giving the BCD code for decimal 8 as 1000. Likewise, if decimal input is 7, then High shows on outputs Y0, Y1, Y2 (and LOW on Y3), hence providing BCD output as 0111.

Decimal

Digit

BCD Code

Y3            Y2                Y1                Y0

0

0                 0                0                     0

1

0                 0                0                     1

2

0                 0                1                     0

3

0                 0                1                     1

4

0                 1                0                     0

5

0                 1                0                     1

6

0                 1                1                     0

7

0                 1                1                     1

8

1                 0                0                     0

9

1                 0                0                     1

Truth Table of Decimal to BCD encoder

2200_Logic diagram for Decimal to BCD Encoder.png

Fig.(b) Logic diagram for Decimal to BCD Encoder


Related Discussions:- Draw the logic circuit of Decimal to BCDencoder

Explain the ccitt hierarchical structure of switching, Explain the CCITT hi...

Explain the CCITT hierarchical structure of switching using block schematic. Hierarchical network are able of handing heavy traffic where needed, and at similar time use mini

Illustrate the application of e-commerce in home banking, Illustrate the ap...

Illustrate the application of E-Commerce in Home Banking. Home Entertainment: E-commerce has show the way to HOME ENTERTAINMENT. The video aspect generally includes a la

difference among primary and secondary storage device, In primary storage ...

In primary storage device the storage capacity is fixed. It has a volatile memory. In secondary storage device the storage capacity is not limited. It is a nonvolatile memory. Prim

What is stack, Stack is a portion of RAM used for saving the content of Pro...

Stack is a portion of RAM used for saving the content of Program Counter and common purpose registers. LIFO stacks, also called as "push down" stacks, are the conceptually easi

What is a system call, What is a system call? A  system  call  is  a  r...

What is a system call? A  system  call  is  a  request  made  through  any  program  to  the  operating  system  for performing tasks, picked by a predefined set, that the said

Call the user methods by creating the object, Make a class library and desc...

Make a class library and describe class 'User'. In User class describe the public, protected and Friend functions. Make a console application andadd a reference to this library and

Determine 1''s complement representation of decimal number, 1's complement ...

1's complement representation of decimal number of -17 by using 8 bit representation is ? Ans. (17) 10 = (10001) 2 In 8 bit = 00010001 1's Complement = 11101110

Describe the uses of credit cards and smart cards, Credit cards and smart c...

Credit cards and smart cards Credit cards comprise a magnetic stripe on the back made up of iron-based particles in a plastic film. Stripe is split up into 3 tracks which a

Bit manipulation techniques, We can also use the logical operators to numbe...

We can also use the logical operators to numbers directly and  perform simple bit manipulation . The operators are     &  Bitwise AND     |  Bitwise OR     ^  Bitwise exclusiv

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd