# Digital Logic Gates

Discussion in 'General Electronics Chat' started by susi, Jun 4, 2004.

1. ### susi Thread Starter Active Member

Jun 4, 2004
31
0
Hi to all,

This is my first post...I hope I'll be the regular user of this useful forum of Circuits.I am doing BCS(Bachelor of Computer Science) and I have two subjects of circuits.One is Circuit Theory(Physics) and the other is Digital Logic Design(Computer Science),in which we study about different conversions of a digit especially to convert a particular digit into binary form,and about Logic Gates etc.
I have a difficulty in understanding Logic Gates OR,AND and their combinations..their functionalities....I'm fed up with all of this as some friend of mine also stole my Text Book of this subject in which it was briefly descibed the functionalities and their usage.I gave him the book in order to help in making assignment but....all it went into vain..it's my advice that don't give ur things to your freinds even not ur close friends in which you have a strong faith n trust..Pray for me.I have only 4 days in preparing myself for this course as examz are on my head and I don't know how can I cover it all...
Waiting for good a response,
*~*Susi*~*

2. ### haditya Senior Member

Jan 19, 2004
220
0
hi
a gate is a ciruit with one or more input and a single output... a logic gate is a circuit that switches between precisely two states (high 1 or low 0)...(although triststate logic has three states--- the third being a state of high impedence)... but lets not consider that at the moment.

of these NOT AND & OR constitue a group called "basic gates"... the other gates of NAND, NOR, XOR, XNOR are derived from these gates.
NAND and NOR gates can be used for constructing every other gate... hence they are called Universal Building blocks.

for construction using NAND you will require
name of gate no. of gates
NOT 1
AND 2
OR 3
NOR 4
XOR 5

for construction using NAND you will require
name of gate no. of gates
NOT 1
AND 3
OR 2
NAND 4
XNOR 5

Try and construct them ur self........ if u cant msg back .... i'll try and get the logic diagrams done....
and also check out the SITE

3. ### susi Thread Starter Active Member

Jun 4, 2004
31
0
hi,

thx for telling me in the detail...but still m not able to understand the implementation of NAND and NOR gates and why these gates are called Universal gates also I wud like to know the method of Karnaugh Map and Quine Mc.cluskey..it will b gud if u give me a useful link.I am sure I will get zero in the exam as there are only 2 days remaining..
Waiting for a response,
susi

[m attaching one file..plz tell me that this can help me in making Logic gates diagrams or not.]

4. ### haditya Senior Member

Jan 19, 2004
220
0
I HAVE ATTACHED A FILE OF HOW NAND GATES ARE USED AS UNIVERSAL BUILDING BLOCKS.
CONSTRUCT THE GATES USING NOR SIMILARLY.

TAKE THIS HINT:- WHILE CONSTRUCTING AND GATE WITH NOR USE THE LOGIC DIAGRAM OF THE OR GATE WHEN CONSTRCTED USING NAND
AND WHILE CONSTRUCTING OR GATE WITH NOR USE THE LOGIC DIAGRAM OF THE AND GATE WHEN CONSTRCTED USING NAND

File size:
20.5 KB
Views:
64
5. ### cheapbeersucks New Member

Feb 16, 2008
1
0
There's alot of resources out there to get familiar before a test. You could spend less time making frowny emoticons and look em up.

6. ### hgmjr Moderator

Jan 28, 2005
9,030
214
Try this link to the material on digital logic gates contained in the AAC ebook.

OOOOPPPPSSS!!!!! I just realized that this thread has been dead for eons in forum years.

hgmjr