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Hello everyone, in this lesson we will take a look at the working conditions of the M.2 interface
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The working conditions of the M.2 interface are relatively simple, only power supply, reset and bus
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Needless to say, the power supply of the M.2 interface is generally 3V power supply
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Reset
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The reset signal is the platform reset signal
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This reset signal is generally sent by IO
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The M.2 hard drive is actually a PCIE device
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The M.2 hard disk occupies a total of 4 sets of PCIE buses,
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that is, 16 data lines plus 2 clock lines
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There are also clock request signals for PCIE devices
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Let's take a look at the M.2 interface on the right
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The pile on the left is all PCIE buses, with a total of 18 wires
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Further down, there is an identification signal here,
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which is used to identify whether the M.2 hard disk inserted into the SATA bus or the hard disk of the PCIE bus
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When inserting the hard disk of PCIE bus, this pin is floating
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When inserting the hard disk of SATA bus, this pin is grounded
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The right side is the hard disk power supply
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Here is a REQ clock request signal
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The hard disk needs to pull this signal low to have the clock of the PCIE bus.
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There is also a platform reset signal on it, which is used to reset the hard disk
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These are the working conditions of the M.2 interface, which are relatively simple
