COUNTERS IN SHIFT REGISTER
COUNTERS IN SHIFT REGISTER
Basically, Counters in shift registers are classified into two types such as ring counter as well as Johnson counter.
RING COUNTERS
Basically, this is a shift register counter in which the first FF output can be connected to the second FF and so on The last FF output is once more fed back to the first flip flop input, that is ring counter.
| CLK Pulse | Q1 | Q2 | Q3 | Q4 |
0 | 1 | 0 | 0 | 1 |
1 | 1 | 1 | 0 | 0 |
2 | 0 | 1 | 1 | 0 |
| 3 | 0 | 0 | 1 | 1 |
JOHNSON COUNTERS
Basically, this is a shift register counter in which the first FF output can be allied to the second FF and so on and the last flip flop’s inverted output can be once more fed back to the first flip flop’s input.
CLK Pulse | Q1 | Q2 | Q3 | Q4 |
0 | 0 | 0 | 0 | 1 |
| 1 | 0 | 0 | 0 | 0 |
2 | 1 | 0 | 0 | 0 |
| 3 | 1 | 1 | 0 | 0 |
4 | 1 | 1 | 1 | 0 |
| 5 | 1 | 1 | 1 | 1 |
6 | 0 | 1 | 1 | 1 |
| 7 | 0 | 0 | 1 | 1 |
