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Hello everyone, in this lesson we will learn about the workflow of the digital interface

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The workflow of the digital interface can be simplified as:

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power supply, HPD, screen reading, display signal

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Both HDMI and DP follow this process

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Let's take the HDMI interface as an example

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First is the power supply

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The power supply of the HDMI interface is 5V

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With the power supply, inserting the screen cable 5V will give the screen

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After the screen receives 5V, it will return a high level HPD

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This HPD is generally for the internal display chip, and it is for the CPU on the mainboard.

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When the CPU receives a high-level HPD signal, it knows that a display device has been plugged in

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Next, the screen data will be read through the DDC bus

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After reading the screen data, a display signal will be sent through the data line and the clock line

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After the screen receives the display signal, there will be a picture

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At this point, the workflow of the HDMI interface is over.

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The only difference between DP interface and HDMI interface is that

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it uses AUX bus instead of DDC bus and clock line

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Ok, so that's the workflow of a digital interface