This document discusses binary coded decimal (BCD) and decimal decoders. It begins by introducing the team members and then provides information about BCD, including that each decimal digit is represented by 4 bits. It describes how BCD is commonly used in electronic displays. It then discusses decimal decoders, including how they work to decode a BCD input into one of ten decimal outputs. It provides examples of 2-4 and BCD to decimal decoders. It concludes by discussing other types of decoders and how decoders can be used in logic design.

1. Welcome to our presentation

2. BCD & Decimal Decoder

3. Md.Aklasur Rahman Robin 162-15-7708
Md. Rakibul Hasan 162-15-7735
Pritam Chandra Shil 162-15-7882
Md. Ariful Islam 162-15-7885
Our team members

4. BCD

5. About BCD
In computing and electronic systems,
binary-coded decimal (BCD) is a class of
binary encodings of decimal numbers
where each decimal digit is represented by
a fixed number of bits, usually four or eight.
Special bit patterns are sometimes used for
a sign or for other indications

6.  Binary coded decimal (BCD) is a system of writing
numerals that assigns a four-digit binary code to
each digit 0 through 9 in a decimal (base-10)
numeral.The four-bit BCD code for any particular
single base-10 digit us
is its representation in binary notation , as follows :
0=0000, 1=0001,2=0010.

7. BCD Sum

8. BCD Adder circuit

9. BCD in electronics
 BCD is very common in electronic systems where a
numeric value is to be displayed, especially in systems
consisting solely of digital logic, and not containing a
microprocessor.
 By employing BCD, the manipulation of numerical data
for display can be greatly simplified by treating each
digit as a separate single sub-circuit. This matches
much more closely the physical reality of display
hardware—a designer might choose to use a series of
separate identical seven-segment displays to build a
metering circuit

10. Decimal Decoder

11. Rules of Decimal Decoder
Digital information represented in some
binary form must be converted into some
alternate binary form.
n to -2 𝑛-line Decoder.
Only one of the 2 𝑛 outputs lines responds,
with a logic-1, to a given input combination
of values on its n-input

12. 2 to 4 binary Decoder

13. 2 to 4 binary decoder diagram

14. BCD to Decimal Decoder
BCD Decoder have four inputs and 10 out
puts.
The four bit BCD input is decoder to
activate one of the ten outputs.
Its accepts four active high BCD inputes ans
provides 10 independent active low
outputs.

15. Other type of Decoders
 Function-specific decoders with less than 2 𝑛
outputs exist.
 Example: Decoder with 4 inputs and 10 outputs in
which a single responding output line corresponds
to a combination of the 8421
code.
Example : Four input , seven output decoder that
accepts the 4 bit of the 8421 code and is used to
drive a seven-segment display .

16. Logic Design Using Decoders
 An n-To-2 𝑛 line decoder is a minterm generator.
 By using or-gates in conjuncation with an n-To-2 𝑛
line decoder ,realizations of Boolean funcation are
possible.
 Do not correspond to minimal sum-of-products.
 Are simple to Product. Particularly convenient
when serveral functions of the same variable have
to be realized.

17. Weighted coding scheme or BCD code
Decimal Digit BCD
0 0000
1 0001
2 0010
3 0011
4 0100
5 0101
6 0110
7 0111
8 1000
9 1001
.
Forbidden codes:
1010,1011,1100,1101,1110,1111

18. BCD to Decimal
Decoder
BCD to decimal decoder accept a binary
coded decimal and activate one of ten
possible decimale digit indications.
IC: 74hc42
QUESTION: Assume the inputs of the
74hc42 decoder are the sequence
0101,0110,0011 and 0010.
Answer: All lines are HIGH except for one
active out active output ,which id LOW.
The active outputs are 5,6,3 & 2 in that
oder.
BCD/DEC