RMII interface with MII Management Bus

[Jeinstei]

Hi-

We have a Micrel chip that runs with an RMII interface with an MII management bus. Do the ReadMII/WriteMII/GetMIIResult methods work? They say that they only work in MII mode, but does this mean that they only work if the Management Bus is enabled?

Thanks,

Josh

[Jeinstei]

Thanks for the help with this! I guess our Management Bus is having its own problems then; I'm going to have to look into this!

[LadislavVadkerti · Accepted solution]

Hi,

yes, they work in both modes, MII and RMII. Historically there was a third mode (currently hidden), which did not have a management bus. Without that mode the hint is confusing and it should be changed. And, of course, if you disable the management bus, the methods are also useless. Thank you for pointing out.

Ladislav

[Jeinstei]

Ladislav-

There looks to be another problem though. ETHn_GetMIIResult() ALWAYS returns an ERR_OK accroding to the driver, meaning that ERR_BUSY is never returned. This means a manual delay has to be added on register reads.

[LadislavVadkerti]

If the OnMIIFinished event is enabled, it signalizes that the register value has been received. If you turn it off, the GetMIIResult will test the completion flag.

[Jeinstei]

Ah-HA! I see it now. Interesting. I appreciate the assistance!