Digital Circuits & Design, 1st Education by Pearson

10.10 | Chapter 10

10.2.5 | Modulus-8 Asynchronous (Ripples) Up Counter

Modulus-8 (MOD-8) asynchronous or ripples up counter uses 3

∵

28

3

=

()

number of

T-ip-ops. First T-ip-op, FF0 is clocked by external clock pulse, C

P

0

. Output, Q

0

of

T-ip-op, FF0 is given to clock pulse, C

P

1

of successive T-ip-op, FF1. Further, output, Q

1

of T-ip-op, FF1 is given to clock pulse, C

P

2

of successive ip-op, FF2.

T

0

1

=

,

T

1

1

=

and

T

2

1

=

CQ

P

1

0

=

and

CQ

P

2

1

=

Figure 10.14 shows the logic diagram of MOD-8 asynchronous (or ripples) up counter.

MOD-8 asynchronous up counter counts 8 (2

3

) clock pulses and counts sequence from 0, 1,

2, 3, 4, 5, 6, 7 and 0 as shown ...