根据应用的时钟脉冲,计数器有两种类型。这些计数器是:异步计数器和同步计数器。
在异步计数器也称为纹波计数器中,不同的触发器由不同的时钟触发,而不是同时触发。在Synchronous Counter 中,所有触发器都以相同的时钟同时触发,并且 Synchronous Counter 在操作中比异步计数器快。
让我们看看这两个计数器之间的区别:
S.NO | Synchronous Counter | Asynchronous Counter |
---|---|---|
1. | In synchronous counter, all flip flops are triggered with same clock simultaneously. | In asynchronous counter, different flip flops are triggered with different clock, not simultaneously. |
2. | Synchronous Counter is faster than asynchronous counter in operation. | Asynchronous Counter is slower than synchronous counter in operation. |
3. | Synchronous Counter does not produce any decoding errors. | Asynchronous Counter produces decoding error. |
4. | Synchronous Counter is also called Parallel Counter. | Asynchronous Counter is also called Serial Counter. |
5. | Synchronous Counter designing as well implementation are complex due to increasing the number of states. | Asynchronous Counter designing as well as implementation is very easy. |
6. | Synchronous Counter will operate in any desired count sequence. | Asynchronous Counter will operate only in fixed count sequence (UP/DOWN). |
7. | Synchronous Counter examples are: Ring counter, Johnson counter. | Asynchronous Counter examples are: Ripple UP counter, Ripple DOWN counter. |
8. | In synchronous counter, propagation delay is less. | In asynchronous counter, there is high propagation delay. |