[eepro100] i82559 w/o EPROM.

Donald Becker becker@scyld.com
Fri, 8 Dec 2000 13:07:42 -0500 (EST)


On Fri, 8 Dec 2000, Bjorn Eriksson wrote:

> > The MAC address isn't really the problem.  You can use
> >   ifconfig ... hw ether 00:11:22:33:44:55
> >
> > The unavailable issue is that the driver reads the transceiver type and
> > MII address from the EEPROM, and without this info the driver
> > will not work.
> 
>  Ok, I guess we'll buy 4096 addresses for $500 and use ifconfig for that.

There are other ways to get a set of station addresses besides getting an
IEEE vendor number assignment.  The advantage of your own IEEE assignment is
that network sniffers can identify the device type when tracking down
network problem.

> I'm not sure about 'transceiver type' and 'MII address' though. [The term
> 'transceiver' doesn't appear in "GD82559ER Fast Ethernet PCI Controller"
> data sheets - odd].

The "PHY" type on the board is "MII transceiver".

>  Say we were to add a serial EPROM to our design, what values should we put
> into it?

The real 82557/58/59 manuals (not the online document!) has the EEPROM
content description.

>  Some quotes from the 82559ER pdf document:
...
>  and <<The 82559ER does not support external PHY devices and does not expose
> its internal MII bus.>>

The i82559 chip is constructed as two internal chips, the i82557 and the
i82555 transceiver ("PHY"), combined onto one die.  The i82555 is accessed
over a serial connection exactly as on the original two chip design.

>  ... The 82559ER CSMA/CD unit
> interfaces the internal PHY unit through a standard Media Independent
> Interface (MII), as specified by IEEE 802.3, Chapter 22. This is a 10/100
> Mbps mode in which the data stream is nibble-wide and the serial clocks
> run at either 25 or 2.5 MHz.>>

There is no reason anyone should need to know this.

>  Some uninitiated guesswork on my part - could 'Primary interface chip' and
> 'Secondary interface chip' be:
> 
> <<
> MDI Register 2: PHY Identifier
> 15:0 PHY ID (high byte) Value: 02A8H
> MDI Register 3: PHY Identifier
> 15:0 PHY ID (low byte)  Value: 0154H

This is the transceiver ID.  It's a combination of the Intel's IEEE ID and
the part version number.  It's unimportant here.

>  ? I.e 0x02A8 and 0x0154? Probably not :-/ It seems to me that only the 5
> LSBits and the MSBit of phy[0] (read from eprom[6]) are used.

That's the value.  It should 

> > I'm not certain what you mean by this.  Only 3Com has two slots for MAC
> > ("station") addresses.  The first is the 3Com assigned permanent address.
> > The second is the station address that is actually used, which is usually
> > the same as the first.
> 
>  Ok, that was a misunderstanding on my part. I read "transceiver and station
> address information" as meaning the MAC has two adresses.

The  MAC/station address is the 00:11:22:33:44:55 value.
The transceiver address is the MII address, 1-31, that the transceiver is
jumpered for.

Donald Becker				becker@scyld.com
Scyld Computing Corporation		http://www.scyld.com
410 Severn Ave. Suite 210		Second Generation Beowulf Clusters
Annapolis MD 21403			410-990-9993