EE 105 Computer Logic Design
Lecture 17
STORAGE ELEMENTS: FLIP-FLOPS
State of a latch or flip-flop is switched by a change in the
control input; this momentary change is called a trigger
Transition it causes is said to trigger the flip-flop
D latch wit

EE 105 Computer Logic Design
Lecture 25
Memory and Programmable Logic
Memory Unit: A device to which binary information is
Transferred for storage
Retrieved when needed for processing
When data processing takes place
Information from memory is transf

EE 105 Computer Logic Design
Lecture 15
Synchronous Sequential Logic
Cell phones, PCs, digital cameras, personal media players
etc have the ability to send, receive, store, retrieve,
and process information represented in a binary format
All these device

EE 105 Computer Logic Design
Lecture 24
Other Counters
Counters can be designed to generate
any desired sequence of states
A dividebyN counter (or moduloN counter) is a counter
that goes through a repeated sequence of N states
Sequence may follow the

EE 105 Computer Logic Design
Lecture 26
Types of Memories
In random-access memory,
the word locations may be thought of as being separated in
space, with each word occupying one particular location.
In sequential-access memory,
the information stored

EE 105 Computer Logic Design
Lecture 16
STORAGE ELEMENTS: LATCHES
Latches : Storage elements that operate with signal levels
(rather than signal transitions)
Latches are said to be level sensitive devices
Flip-flops: Storage elements controlled by a cl

EE 105 Computer Logic Design
Lecture 23
Chapter 6: Registers and Counters
Synchronous Counters
A common clock triggers all flip-flops simultaneously in
synchronous counters
If T = 0 or J = K = 0
Flip-flop does not change state
If T = 1 or J = K = 1
F

EE 105 Computer Logic Design
Lecture 21
Chapter 6: Registers and Counters
6.1 REGISTERS
A Register is a group of flip-flops
n-bit register has n flip-flops
Can hold n bits of binary data
A Counter is essentially a register that goes through a
predeter

EE 105 Computer Logic Design
Lecture 21
Chapter 6: Registers and Counters
Counters
A register that goes through a prescribed sequence of
states upon application of input pulses is called a counter
Input pulses
may be clock pulses or pulses from some ex

EE 105 Computer Logic Design
Lecture 18
Flip-Flop Characteristic Tables
Characteristic table defines the logical properties of a
flip-flop by describing its operation in tabular form
Flip-Flop Characteristic Tables
Characteristic tables define the next

EE 105 Computer Logic Design
Lecture 20
DESIGN PROCEDURE
Design procedures specify hardware that will implement a
desired behavior
Manual design effort for small circuits
But industry relies on automated synthesis tools for designing
massive integrated

EE 105 Computer Logic Design
Lecture 19
Mealy and Moore Models
We distinguish between two models of sequential circuits
based on the way the output is generated
The Mealy model
Outputs are functions of both present state and inputs
The Moore model
Ou

EE 105 Computer Logic Design
Lecture 14
Encoders
An encoder performs the inverse operation of a decoder
An encoder has
2n (or fewer) input lines
n output lines
Output lines (as an aggregate) generate the binary code
corresponding to the input value
E

EE 105 Computer Logic Design
Lecture 11
Binary Adder-Subtractor
The most basic arithmetic operation performed by Digital
computers is the addition of two binary digits
0 + 0 = 0, 0 + 1 = 1, 1 + 0 = 1, and 1 + 1 = 10
When both are equal to 1, binary Sum c

EE 105 Computer Logic Design
Lecture 12
Binary Subtractor
Subtraction of binary numbers can be done most
conveniently by means of complements
Remember that the subtraction A - B can be done by
taking the 2s complement of B and adding it to A
2s complem

EE 105 Computer Logic Design
Lecture 13
Decoders
Discrete quantities of information are represented in
digital systems by Binary Codes
n Bits Code
2n distinct elements of coded information
A decoder circuit converts binary information from:
n Input Line

EE 105 Computer Logic Design
Lecture 01
Welcome
Instructor
Dr. Muhammad Gufran Khan
PhD, MSc EE (Sweden), BSc EE (UET, Lahore)
Assistant Professor
Email: m.gufran@nu.edu.pk
Course Info
Course Title
EE105 Computer Logic
Design
Credits Hours: 3+1
Pre/C

EE 105 Computer Logic Design
Lecture 10
Combinational Logic
Logic circuits may be combinational or sequential
A Combinational Circuit
Consists of logic gates
Outputs are a function of the present inputs
Specified logically by a set of Boolean functio

EE 105 Computer Logic Design
Lecture 08
Review
Canonical Forms
Minterms and Maxterms
Conversion between canonical Forms
Standard Forms
SOP and POS
Two and Multilevel Implementation
Other Logic Operations and Gates
Positive and Negative Logic
Inte

EE 105 Computer Logic Design
Lecture 07
Review
Boolean Algebra
Laws, Rules & Theorems of Boolean Algebra
Boolean Analysis of Logic Circuits
Simplification using Boolean Algebra
Standard forms of Boolean Expressions
Canonical and Standard Forms
Minter

EE 105 Computer Logic Design
Lecture 05
Recap
Binary Codes
BCD Code
Gray Code
ASCII Code
Error Detecting Code
Parity Bit
Binary Storage and Registers
Binary information in a digital computer must
have a physical existence in some medium for
storing

EE 105 Computer Logic Design
Lecture 04
Recap
2s Complement
1s Complement
Unsigned Binary
Signed Binary
Signed-2s complement vs. Signed Magnitude
Recap
Range of Binary Numbers
Range and Overflow
Floating Point representation
Binary Codes
Digital

EE 105 Computer Logic Design
Lecture 06
Boolean Algebra
Algebra for binary values
Developed by George Boole in 1854
Variable:
A variable is a symbol usually an uppercase letter
used to represent a logical quantity
A variable can have a 0 or 1 value

EE 105 Computer Logic Design
Lecture 02
Number Systems and Codes
Decimal Number System
Binary Number System
Hexadecimal Number System
Octal Number System
Decimal Number System
Ten unique numbers (called digits): 0,1,.,9
Combination of digits to repr

EE 105 Computer Logic Design
Lecture 03
Complements of Numbers
Complements are used in digital computers to
simplify the subtraction operation and for logical
manipulation
Simplifying operations leads to simpler, less
expensive circuits to implement the