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That chip is a TCP/IP microcontroller with embedded PHY. You don't talk to the PHY directly, the microcontroller does. The SPI inferace you talk with the MCU has no concept of PHY address. …

PHY chip output stages vary; some have only current sink on/off output, some have multiple current levels. …

We can't know why chip designers chose those pins as straps - many other PHYs have them straps too. But you can surely rearrange resistors so that there are no stubs.

The MDIO bus is not open-drain, when a device transmits data, the pin will change to push-pull output. So yes, it can cause damage, but as the outputs will not be constantly driving the pins to opposi …

The datasheets usually provide electrical characteristics what voltages to expect at given load current and what kind of rise/fall times to expect at given load capacitance. You should sum up how much …

It is possible to add extra magnetics because that is how external PoE injectors and extractors work. But Ethernet is already a tranformer coupled isolated interface which by specifcation must withsta …

Actually that is not a loopback configuration as it means connecting a single PHY to itself. I assume you mean you want to connect two PHYs in back-to-back configuration to make an Ethernet repeater. … (Disclaimer, I've not used this PHY in PHY-to-PHY mode). …

I don't think it matters much because your path from magnetics to connector must be equal no matter which PHY you use. … If you want you can of course terminate the pins that the PHY does not use in same way than the pairs the PHY does use. …

Unless you mean pins 4,5,7,8 at the PHY side, in which case you connect them how PHY requires them to be connected. …

An example PHY requires 12 IDLE symbols to synchronize. So likely it does not synchronize if there is no IDLE symbols. It may be possible to bypass the scrambler. … So the PHY would never signal that received data is valid and PHY would not output data. …

You likely can't measure the inductance as it is very small. It's not an inductor. The part is a ferrite bead, with 600 ohms impedance at 100 MHz. You will find the exact part number from the Nucleo b …

Voltage levels swings at the PHY side are usually biased around the PHY analog supply voltage, which might be 3.3V, so it depends on the PHY selected. … At the PHY side of the transformer you have the signals and ground and supplies for the PHY chip, and you must protect the pins of the PHY chip in reference to ground and supplies. …

If your MCU has no gigabit interface (GMII/RGMII) then you don't have gigabit interface to the PHY and then the PHY can't form a gigabit link either. …

Your topic says about gigabit Ethernet but ask about 100Base-TX. First the 100Mbps data is grouped to 4-bit symbols of which are then expanded to 5-bit symbols using 4b5b coding, resulting into 125 M …

1000Base-T and 1000Base-TX are both full duplex only. T uses all four pairs bidirectionally, while TX uses two pairs to transmit and two pairs to receive. 100Base-TX can be full or half duplex. It use …