Page 85 - Digital Electronics by harish
P. 85
Least Significant Bit (LSB) and the output D is called the Most Significant Bit (MSB). The
CLEAR (Cr) input of all the FFs are connected to ground through the Master Reset switch.
When the Master Reset switch is pressed, all the FFs are cleared and the counter
output DCBA is 0000. During the negative edge of the first clock pulse, FF A will be toggled
i.e. the output A changes from 0 to 1. At this time, the outputs of all other flip-flops will not
change.Hence, the counter output DCBA is 0001.
Input Output
Clock D C B A
Reset 0 0 0 0
1 0 0 0 1
2 0 0 1 0
3 0 0 1 1
4 0 1 0 0
5 0 1 0 1
6 0 1 1 0
7 0 1 1 1
8 1 0 0 0
9 1 0 0 1
10 1 0 1 0
11 1 0 1 1
12 1 1 0 0
13 1 1 0 1
14 1 1 1 0
15 1 1 1 1
16 0 0 0 0
During the application of the second clock pulse, FF A will be toggled once again
from 1 to 0. This will give a negative edge triggering pulse to FF B and hence FF B also
toggles from 0 to 1. The counter output DCBA will become 0010.
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