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On several occasions, we should use a single clock cycle pulse to start an event or report the end

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of an event, this lecture will explain how to generate the single cycle pulse in each of us.

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A single psychopath generates a circuit, has an input and an output, it generates a one clock cycle

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with pulse on its output when it detects a rising signal on its input.

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Let's consider a clock signal and a white with pulse.

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Then as shown in this figure, the output should be a single cycle.

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Narrow pulse.

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The proposed path generates a circuit, has two estates, wait for one and wait for the wait for one

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state is the initial estate during which the input carries the logic value zero.

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In this estate, the circuit is waiting for a high voltage level on the input signal.

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The wait for zero state is when the input signal carries the logic value one during this to say the

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circuit is waiting for a low level voltage on the input signal.

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As soon as the circuit detects the one logic value on the input when it is in the wait for one state,

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it goes to the wait for zero state.

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And assigns the lodging value one to the output, in other cases, the output is zero.

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This results in a single cycle, positive pulse on the output.

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The design detects a rising edge on the input signal when it is in the wait for one state and the logic

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value of one is detected on the input signal.

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In this case, it assigns the logical value of one to the output signal and goes to the wait for zero

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state.

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It goes back to the wait for one state when the input changes to zero.

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OK, let's ascribe the design and each of us.

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We need a function that receives the one bit input and returns at one bit output.

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We can define a static variable to represent the design state, we need to temporary variables, one

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for the state and the other for the output.

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Then we need a state machine with two states.

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After that, the state and output should be modified.

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The second, the texturizing edge on the input signal, if it is in the W one or wait for one state

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and the input signal is one.

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In this case, it goes to the W zero or right four zero state and puts a logging value one on the output

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signal.

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If the circuit is in the W zero state and the input is also one, the second stays in that state.

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It goes to the W one state as soon as it receives a zero on its input.

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Now, let's simulate and synthesize the code corrida with a socialist project and add design and test

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fires to the project, you can find the files attached to this lecture.

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How we look at it has been Sourcefire, it consists of three times the first and last loops, put the

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logic value zero on the design function input argument for five cycles.

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And then we drill for loop puts a logic value one on the design input argument for five cycles.

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Therefore, it generates a five clock cycle pulse on the design input.

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Now, let's simulate the design.

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Down to chose the appearance of a single psychopath's on the.

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We can then synthesize the code and make sure our description is synthesized into a single cycle article

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code.

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Then run the article CECO Simulation and check the waveforms.

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We have generated a single cycle pulse in this lecture.

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The question is, how can we generate a regular single cycle pulse with a constant period?

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The next lecture will cope with this question.

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This is our takeaway message to the state machine can be used to detect an edge on a signal.

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Now, the quiz question modified the pulse generator code such that the outward pulse is generated on

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the following edge on the input signal.