Bistable Element :
The fundamental building block of memory element is a bistable element. Bistable element is made up of 2 stable states '0' and '1'. Below diagram of Cross coupled inverter is an example of a simple bistable element.
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| Cross Coupled Inverters |
The cross coupled inverter circuit has no inputs but has two output Q and Qbar. Since this circuit have only two stable states Q=0 and Q=1, this circuit is said to be bistable. However the main limitation is that this circuit don't have any input to directly control the state. This limitation makes them less practical for most applications where controlled storage and manipulation of data is required.
To address this limitation bistable elements like Latches and Flip flops have been developed.
