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How can we describe an officer in this lecture, explain the template code and coding style to describe

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an FSM in each of us?

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Most of the practical sequential circuits can be described with FSR.

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We are already familiar with the essential elements in an officer to describe an officer in us, we

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need a C C++ function.

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An enumeration data type can define all the states using the FSM on their description, then we need

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to define a set of static variables as registers to define states in deficit.

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Responding to each state, we define a variable to represent the next state's value.

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The idea is that we are not going to change the register value several times throughout the code, therefore,

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as a coding ASI, we define the next state variables and change them throughout the function and at

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the end we assign them to the state registers.

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Then we define a variable corresponding to each output argument in the function.

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Again, we modify these variables as the output value and assign them to the output arguments at the

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end of the function at the heart of the function.

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Buddy, we have a switch case statement that defines all the FSM transitions.

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At the end of the function, we modify the state registers and assigned outputs.

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Let's explain how to use this template to describe our combination lock example explained earlier in

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the section.

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As explained in the previous lectures, our combination lock should find the sequence of two, three,

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four and six through five states to open the lock.

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Let's write the code for this combination lock.

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First, it is a good practice to define an enumeration type to represent all the states, then we should

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define the design of function, which receives one form with input and generates a binary output.

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We can have the function arguments interfaces now.

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Registers represent the Sukkoth states in this example, we need one state to register that can be defined

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using the C static variable according to our template.

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Now we should define a variable that holds the next value of the circus.

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States register.

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Know that this technique prevents changing the registered value several times throughout the code.

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Now, let's define a variable that holds the output value throughout the code.

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Again, this variable prevents assigning different values to the function argument several times throughout

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the code.

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Now we need to each case a statement to represent the state transitions.

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The suitcase has five cases and a default, if you are in a state that's zero and the input is two,

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then the next state would be as to otherwise the next state is zero.

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If you are in the states, too, and the input is three, then the next state would be as two three,

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otherwise the next state is as zero.

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If you are in a state as two, three and then put is four, then the next state would be as two, three,

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four, otherwise the next state is a zero.

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If you are in a state as two, three, four and the input is six, then the next state would be two,

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three, four, six.

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Otherwise the next state is a zero.

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If you are in state as two, three, four, six, then the door is open and the second stays in that

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state until somebody locked the door again.

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Note that for the sake of simplicity, the lock mechanism is not shown in the scope.

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Finally, we should change the design of state and assigned output value to the corresponding function

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arguments.

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In the next lecture, I will explain how to synthesize the scope inviter Satchel's.

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These are our takeaway messages, we use a static variables in C to define the states in our telescope.

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It is a good practice not to change the static registers several times throughout the code.

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So defining nextstep that variables to keep the intermediate state value is a promising technique.

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An input signal to our combination lock circuit that resets the state machine and locks the door.