CHAPTER 4

Digital
Fundamentals
Tenth Edition

Floyd




Chapter 8
Asynchronous
Counters
Floyd, Digital Fundamentals, 10th ed © 2009 Pearson Education,©Upper
2008 Pearson Education
Saddle River, NJ 07458. All Rights Reserved

, Summary
Counting in Binary
As you know, the binary count sequence follows a
familiar pattern of 0’s and 1’s as described in
Section 2-2 of the text.
000 LSB changes on every
001 number.
010
The next bit changes
011 on every other number.
100
The next bit changes on
101
every fourth number.
110
111



Floyd, Digital Fundamentals, 10th ed © 2009 Pearson Education, Upper Saddle River, NJ 07458. All Rights Reserved

, Summary
Counting in Binary
A counter can form the same pattern of 0’s and 1’s with
logic levels. The first stage in the counter represents the
least significant bit – notice that these waveforms follow
the same pattern as counting in binary.

LSB 0 1 0 1 0 1 0 1 0

0 0 1 1 0 0 1 1 0

MSB 0 0 0 0 1 1 1 1 0




Floyd, Digital Fundamentals, 10th ed © 2009 Pearson Education, Upper Saddle River, NJ 07458. All Rights Reserved