Andreas Gschossmann
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Hello,
I am working with a System on a Module board. On this board there is a Ethernet PHY connected to the MII signals of the microcontroller. My problem is that some of these MII signals are multiplexed with the SPI-function of the microcontroller. I want do not want to use the ethernet PHY on the board. Instead I want to use the SPI-function of these pins.
It is not possible remove the PHY-IC. Also it is not possible to interrupt the according signal paths on the pcb. However it is possible to interrupt the connection to IO-voltage and to supply-voltage of the ethernet PHY.
The SPI-signals are used TTL-inputs and outputs. If I remove the IO-voltage and supply-voltage of the ethernet PHY, is it possible to just connect the SPI-IC to these signals to communicate with the microcontroller? Can this lead to problems?
If there is no voltage at the ethernet PHY, the outputs and inputs are like diodes in reversed direction. Is that right? What will be the behaviour of the protection diodes of the IC? Your feedback would help a lot.
I am working with a System on a Module board. On this board there is a Ethernet PHY connected to the MII signals of the microcontroller. My problem is that some of these MII signals are multiplexed with the SPI-function of the microcontroller. I want do not want to use the ethernet PHY on the board. Instead I want to use the SPI-function of these pins.
It is not possible remove the PHY-IC. Also it is not possible to interrupt the according signal paths on the pcb. However it is possible to interrupt the connection to IO-voltage and to supply-voltage of the ethernet PHY.
The SPI-signals are used TTL-inputs and outputs. If I remove the IO-voltage and supply-voltage of the ethernet PHY, is it possible to just connect the SPI-IC to these signals to communicate with the microcontroller? Can this lead to problems?
If there is no voltage at the ethernet PHY, the outputs and inputs are like diodes in reversed direction. Is that right? What will be the behaviour of the protection diodes of the IC? Your feedback would help a lot.
