Now the memory element also has a clock input which provides timing for changing states. If there was eight, it would be 256 16 bits, 65K and 32 there would be four gigs. If you had four bits of memory, then there would be 16 possibles states. That wouldn't be very much memory but it's just for the sake of explanation that would be the case. Note here if you had one bit of memory, this will equate to two states, one high and one low. Now in memory, the whole idea of memory is that you are going to be retaining certain states. well in the case of combinational, as soon as you made an input, it immediately impacted the output., but with sequential circuits, you can change the inputs and they don't necessarily immediately change the outputs because there might be something going on in memory.

It's the presence of memory that can cause the inputs and outputs to. Remember this is what differentiates the sequential logic circuit from a combinational one. Notice that we have some combinational logic circuitry on both ends, but in between, we have this memory element. Here is a sequential logic circuit and this is just an example. A sequential logic circuit typically has some type of memory element to hold the state of the circuit. Now, this is much like what we discussed in combinational logic. A sequential logic circuit can have any number of inputs and any number of outputs. This section will actually be broken into multiple sections. Hey, we are in 15-3 and in this section, we are going to be looking at sequential logic.

Sequential circuits examples