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Terms explanation
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This video mainly explains the common term meanings and identification methods in schematic diagrams
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We must understand the English term meanings in the schematic diagram
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Because the schematic diagrams are marked in English,
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the definition of chip pins and the meanings of the circuit will be marked in English
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If you understand these English terms,
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you can judge the fault more quickly during maintenance
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Next, let me explain the English identification
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and identification of important signals required for the chip to work
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Important working conditions include power supply, ground, clock signal,
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reset signal, enable signal, wake-up signal, interrupt signal, etc.
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These signals will be marked in different English in the drawing
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The power supply is to provide the voltage and current for the chip to work
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During the working process,
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the power supply cannot be set high, nor can it be pulled low
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If the power supply is pulled down, it is generally called a short circuit
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If the voltage is set high, it may exceed the withstand voltage value of the chip,
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resulting in damage to the chip
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The name of the power supply is generally marked in English with VCC, VDD or PP in the schematic diagram
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For example, in the picture, PP_SOC_S1
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VDD_GPU also refers to the power supply,
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and some will directly identify the power supply voltage
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For example, VREG_S1A_0P752,
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0P752 means that the power supply is 0.752V
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VOUT7_1V8, the power supply voltage is 1.8V
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Grounding
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Grounding is to form a loop for power supply
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If there is no grounding, no current will flow through the equipment
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Without current flowing through the device, the chip will not work
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In the schematic diagram, the ground wire is identified by VSS and GND
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After opening the drawing, check the English of the internal pins
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When VSS or GND is marked, it means that the pin is grounded
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Signal
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In the schematic diagram, the signal is only collectively referred to,
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and generally all lines except the power supply and the ground wires are called signal lines
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The signal line generally only considers the voltage change, not the current
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Because the signal will be pulled down or set up at any time according to the needs of the chip when it is working
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Pulling low means that the signal line has no voltage, and no voltage means 0
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If it is set high, it means that the signal line has voltage,
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and if there is voltage, it means 1
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This is the 0 and 1 in the digital circuit that is often said
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When the chip is working, the signal will be grounded or set high at any time
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to form 0 and 1 to realize different operation commands
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Ok, that's all for this video
