This document discusses counters in digital electronics. It begins by introducing counters as sequential circuits that increment their output value by one each clock cycle, wrapping back to 0 after their maximum count. There are two main types of counters: asynchronous and synchronous. Asynchronous counters have their flip-flops clocked one after another by the previous flip-flop's output, causing a ripple effect. Synchronous counters clock all flip-flops simultaneously with a common clock signal. Examples of 4-bit asynchronous and synchronous counters are also provided with their respective timing diagrams.

1. BASICS OF ELECTRICAL AND
ELECTRONICS ENGINEERING
ASSIGNMENT PRESENTATION
COUNTERS – DIGITAL ELECTRONICS

2. Content
• INTRODUCTION
• BENEFITS OF COUNTERS
• TYPES OF COUNTERS
• ASYNCHRONOUS COUNTERS
• BINARY RIPPLE COUNTER

3. Introduction
• Counters are a specific type of
sequential circuit.
• Like registers, the state, or the
flip-flop values themselves, serves
as the “output.”
• The output value increases by one
on each clock cycle.
• After the largest value, the output
“wraps around” back to 0.
00 01
1011
1
11
1

4. Benefits of counters
• Counters can act as simple clocks to keep track of “time.”
• You may need to record how many times something has
happened.
• How many bits have been sent or received?
• How many steps have been performed in some computation?
• All processors contain a program counter, or PC.
• The PC increments once on each clock cycle, and the next
program instruction is then executed.

5. Counters
Synchronous
Asynchronous

6. Asynchronous Counters
 The flip-flops do not change states at exactly the same time as
they do not have a common clock pulse.
 Output of one flip-flop is connected to the clock input of the
next more-significant flip-flop.
 Its simple and requires less hardware.
 Has speed limitation.
K
J
K
J
HIGH
Q0 Q1
Q0
FF1FF0
CLK CC
Timing diagram
00  01  10  11  00 ...

7. Binary ripple counter
• The counter is called ripple counter because the output of one
flip-flop feed to the clock input of another
• The flip flops respond to negative going clock edge.
• Each flip flop divides the incoming clock pulse frequency by a
factor of 2.
•
• Cumulative delay is a drawback.

8. 4-Bit Asynchronous Counter

9. Synchronous Counter
• Synchronous Counters are so called because the clock input of
all the individual flip-flops within the counter are all clocked
together at the same time by the same clock signal.
• The clock signal is directly applied to all Flip flops in a parallel
sequence.

10. 4-Bit Synchronous Counter

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