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Oct 20, 2021 · Viewed 5k times. 2. I have seen the abbreviation PHY beeing used for a handful of different things within the context of Ethernet: a PHY is a type of Ethernet physical layer (eg. 100BASE-TX, 10BASE-T) a PHY is an Ethernet transceiver IC (eg. an IC that converts 100BASE-TX to MII/RMII) a PHY is a physical layer device (more than just the ...
以太网phy它不关心一个以太网帧里面的内容，进一步以下图示意： 以太网帧结构示意图 它不会去解析一个以太网帧里面的MAC帧头（目的MAC地址、源MAC地址、MAC帧类型）更不会去解析MAC帧的数据，因为它的定位就是物理层，职责是怎么把整个帧从介质上解码出来送给MAC层亦或者怎么把整个帧编码好发到介质上。
A PHY chip or layer converts data between a "clean" clocked digital form which is only suitable for very-short-distance (i.e. inches) communication, and an analogue form which is suitable for longer range transmission. It has no particular clue as to what any of the bits "mean", nor how they should be interpreted or assembled.
Aug 10, 2023 · Using the existing UTMI+ specification as a starting point, the ULPI working group reduced the number of interface signals to 12 pins, with an optional implementation of 8 pins. The package size of PHY and Link IC’s are drastically reduced. This not only lowers the cost of Link and PHY IC’s, but also makes for a smaller PCB.
Sep 6, 2016 · SMSC recommends a distance between the LAN950x and the magnetics of 1.0” at a minimum and 3.0” at a maximum. Confusingly enough, earlier in the same paragraph one can read: Ideally, the LAN device should then be placed as close as possible to the magnetics. I used the excellent LANcheck service from Microchip and the expert reviewing my ...
May 23, 2023 · Current mode (CM) PHYs' drivers are basically open collectors (current sources) so the centre tap is tied to Vcc. Without Vcc tied to centre tap it won't be possible to induce a voltage at secondary. Voltage mode (VM) PHYs, on the other hand, have true differential drivers. It's not a crucial requirement to place a capacitor to the centre tap ...
Sep 1, 2010 · 12. I'm trying to connect an RJ-45 jack with integrated magnetics (Belfuse L829-1X1T-91 datasheet) to an Ethernet PHY chip (Micrel KSZ8041TL datasheet). The TX+/-, RX+/-, and the LED pins are all easy enough to figure out, but I'm not sure what to do with the center taps (TCT and RCT) for the transformers. Should they be connected to 3.3 V power?
What you really need is a different variety of PHY, so called "backplane phy". Those are specifically designed to work with capacitive coupling over PCB traces. The relevant standard is called 802.3ap. Here's a nice overview: Many modern PHYs can be put into a 1000Base-KX mode through a bit of configuration tweaking.
It looks like you have isolated the PHY's power nicely with L10 and bypass caps C69-C74. All you need to do is connect all the PHY grounds together, then make sure that net has exactly one connection to the main ground. That keeps the nasty high frequency loop currents local, but still gives the PHY the same 0V reference as the rest of the board.
Mar 18, 2017 · There are switch IC's that use external phys (you need to have a separate MII interface that goes to a phy), switch IC's that have internal phys (the differential pairs run right into the IC), and switch IC's that do both internal and external. A good example of this is the KSZ8873MLL/FLL/RLL. Depending on the IC you buy the Phys can be ...
