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Hello everyone, today we are going to learn about signals
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Signal in theory, the voltage signal only considers the voltage change,
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the current of the signal is very small, almost no current
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During the operation of the mainboard,
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the signal can be pulled up or down as needed at any time
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In the circuit diagram, signals are represented by arrows
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For example, this kind of arrow, OUT is the output signal,
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IN is the input signal,
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this kind of arrow with two points is called two-way communication
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This is the signal
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The direction of the arrow usually indicates the direction of the signal,
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but occasionally it can be misdrawn
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A signal with an L after it, or this type of signal with an *,
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indicates that the signal is active at low level
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The high and low levels need to be determined by the circuit
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and cannot be limited to a certain value
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Normally, 0V is low, and if there is voltage, it is high
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In digital circuits,
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high levels are represented by 1, or H,
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and low levels are represented by 0, or L
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So that's a brief description of the signal