I'm implementing software GPIO based SMI protocol for a small embedded microcontroller, and got stuck with turnaround bits. As I understand it, after reading 802.3 spec, it consists of two bits, and only the first bit depends on operation - read or write. For write it's always '1', but I can't understand how it is asserted for reading.
And seconf half of my question: I use two gpio pins, one for MDC and the other for MDIO. To set turnaround bits, do I have to drive only MDIO? As far as I understand the standard, MDC is not affected, isn't it ?