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In this lesson,

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we look at the circuit description of the hard disk in the trigger small current related circuits

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How do we find the hard disk of the mobile phone in the drawings?

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For example, we open the mainboard schematic diagram

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and component diagram of Xiaomi 10

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We see that its position number is U5600

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We search it in the circuit diagram

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and we can find its description page, on page 57

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This chip is also called FLASH MEMORY

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First, let's look at the power supply of the hard disk

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We can directly look at the pins of the hard disk chip,

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VCC means power supply

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This power supply is called VREG_L17A_3P0, 3V power supply

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This 3V power supply is given by the power chip,

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and it is given to these pins,

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such as B8, B9, E8, etc.

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Let's look at another way to power the hard disk

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We see VCC on this pin of the hard disk

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These pins are all connected to a line,

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1.2V power supply

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This Xiaomi phone has two lines for power supply,

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one is 3V and the other is 1.2V

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Let's take a look at what else is described on the hard disk?

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We see UFS, UFS means that this hard disk is a UFS hard disk,

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that is, the hard disk particles with relatively fast transmission speed at present

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UFS0_RESET is reset signal of the hard disk,

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which is used by the CPU to reset the hard disk

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UFS0_REF_CLK is clock signal of the hard disk,

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which is also given by the CPU

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We can see which chip the power supply is connected to

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by looking at the circuit diagram,

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which means which chip is coming over

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Like UFSL0, UFSL1,

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these are the transmit data and receive data lines

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They are the data read and write channels between the hard disk and the CPU

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for transmitting high-speed data

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For example, during the boot process,

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the power supply of the hard disk is normal,

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and after the clock and reset are normal,

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the CPU will read the boot program stored in the hard disk through these 8 lines

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After booting, for example,

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we want to store a large-capacity thing,

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insert the mobile phone into the computer,

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and import a video,

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the transmission channel of the video is actually here

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Ok, here is the circuit of the hard disk

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That's it for this lesson