WEBVTT

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Welcome to the state machine introduction lecture and this lecture I'm going to produce how state machines

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operate.

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Let's just start with the state machine definition a state machine is a device that can be in one of

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a set number of stable conditions depending upon its previous condition and on the present values of

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its inputs and what that means is we have different states we can go around it.

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So we have predefined conditions or states that we specify.

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And based upon inputs and also the predefined state that we're currently in we can navigate to different

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states and there are two different common types of state machines.

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There's Meely machine and a more machine a milling machine is a finite state machine whose output depends

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on the present state as well as the present input.

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So that means is if you're in say state a certain state you depending upon what state you're in and

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the input is going to dictate what is the next state that you'll go to.

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And generally these have fewer states than a more machine and the outputs change at clock edges and

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a lot of times I'm most commonly used Milia machines.

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And in this course we'll be only dealing with milling machines but there are also these also react faster

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to inputs.

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So machine input happens right away and then on the clock edge we transition from a state.

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The next one will look at is the more machine a more machine is a state machine whose output depends

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only on the present state.

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So the input doesn't matter.

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There's a specific input and once that it sees that input it goes depending upon the state it's in it

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goes to the next state.

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So generally with a more machine you have more states and a milling machine.

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So you can't say OK if I get the signal if it's a when I go here for the zero I go there it's like no

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once the signal is zero I go directly to that next state.

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There's not no decision making the input change can cause cause change in an output change as soon as

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the logic is done.

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So we don't wait on the clock edge as soon as we see that input output we change state.

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It happens right away.

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In the more machines more logic is needed to decode the outputs since it has more circuit delays.

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Now you're familiar with state machines.

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Let's take a look at how to start designing one.