[U-Boot-Users] MII / RMII

[Ulf Samuelsson <ulf@atmel.com>]

> Ulf Samuelsson wrote:
>> tor 2007-11-29 klockan 19:51 +0100 skrev Guennadi Liakhovetski:
>>   
>>> Hi,
>>>
>>> 1. Does it make sense at all to define CONFIG_RMII without defining 
>>> CONFIG_MII? The question is meant not really theoretical as in what 
>>> meaning RMII has, rather how the macro CONFIG_RMII is supposed to be used? 
>>> For example, tests like
>>>
>>>     
>>
>> I think that if you use an Ethernet and need to differentiate
>> between MII and RMII they should be mutually exclusive.
>> You either define CONFIG_RMII OR CONFIG_MII but not both.
>> If you have a PHY on the chip, then you do not define any of the two.
>>   
> Not quite. I've argued that both CONFIG_MII and CONFIG_RMII are 
> pointless, but if they did have a purpose it would be to set up the link 
> between a MAC and a PHY on the MAC side. The bottom line is that if 
> CONFIGs like this are going to be used for hardware initialization they 
> need to be much more specific.
> 

You need to know which PHY you are going to use,
and you need to know if you are going to connect using RMII or MII
so you need to have some kind of configuration.
Once the configuration for MII/RMII is known, then
each chip driver will have a very few things which can vary.

I think the pin multiplexing is the key thing that could be controlled
by these things.


Each chip will have limited 


> regards,
> Ben


Best Regards
Ulf Samuelsson                ulf at atmel.com
Atmel Nordic AB
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