MDD (MDIO/MDC) library for Teensy

[Edward]

Hi All,

I'm designing an ethernet repeater, and I was looking at ways to debug it. I'm not planning on having anything manage the link, it's just going to be two phy's back to back with the RMII interface. It does occur to me, that having some way to access the MDIO/MDC bus externally would be nice, in case I need to fiddle with any registers. Ideally, I'll get all my straps right the first time, but that's not always the case is it?

Is there a library available/has anyone done this, so I can connect a teensy to the bus and use it for this purpose?

Ed

 

[Edward]

Further to this, I've not found any such library and I'm definitely going to need something to do the job as I actually need to drop in a micro to change a single register at power on. The MDIO interface is pretty similar to I2C, with a data line and a clock line, with one master controlling the clock, and slaves that have unique addresses. There's no minimum speed requirement for the bus, and I only really need to write one register on one slave, so I think this calls for a spot of bit-banging. Does anyone have a good starting point for an efficient way to code sending data out with a clock?