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iPhone mobile phone commonly used bus

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In this video, we mainly explain the RFFE bus

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The RFFE bus is an interface standard for mobile terminal RF front-end control introduced by the MIPI Alliance in 2010

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The RFFE bus consists of a power line and two control lines

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The bus line is simple and easy to deploy

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It enables near real-time control within timing range requirements

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In Apple's machines, it is generally used in the detection line between the baseband and the phone chip

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Through the iPhone bus architecture diagram, we can see

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The RFFE bus used in the middle of the baseband to radio frequency, power amplifier, antenna switch and filter

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This bus is the baseband chip used to detect and control calls

twenty three

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After the RFFE bus of the baseband has a problem, the common faults are as follows:

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No service, signal diving

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In severe cases, the baseband does not work

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For example, after we plug in the phone card, it will show China Mobile

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Then came the mobile signal

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Wait for about 10 seconds, the machine shows no service again

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Wait another 10 seconds or so, it will appear China Mobile

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This fault phenomenon belongs to the signal diving

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Add it down, let's find the RFFE bus in the drawing

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Let's take the iPhone x Qualcomm model as an example

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In the annotation map, we first find the baseband position number

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Go to the drawing to search for the baseband position number

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After searching for the baseband, we base on the English name outside the block diagram

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As long as the English logo RFFE, it represents the bus

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In the current interface, we can see

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RFFE is marked in English outside the block diagram

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That means the line refers to the RFFE bus

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There are many sets of this model

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From RFFE1 to RFFE6, there are 6 groups of RFFE buses

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These 6 groups of buses detect different chips

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Let's go check it out

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After RFFE1 is sent from the baseband, it passes through the fuse resistor, and then connects to the radio frequency

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RFFE3 is sent out through the baseband and then connected to these amplifiers

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The chips that make calls are all detected and controlled by the baseband through the RFFE bus.

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We'll stop here in this lesson