sungem on imac G5

Brad Boyer flar at
Fri Mar 18 10:08:37 EST 2005

On Thu, Mar 17, 2005 at 08:30:47PM +0100, Markus Demleitner wrote:
> Now, I don't even know what a PHY is, really, and thus this cry for
> help:  Is there any way to perform a really deep, deep reset on the
> sungem device?  Is it just that Apple chose some not-quite-known
> PHY in the G5?

This won't really help your bug, but I can explain the purpose of a
PHY chip. This chip implements the physical media layer, such as
10baseT, 100baseTX, etc. It performs low level signal handling,
auto-negotiation, bit encoding (for fiber), and other stuff related
to the actual signal going over the cable. Because of this, you can
buy the different parts of an ethernet card from separate vendors
depending on the features you need. For example, Apple puts chips
that auto-detect crossover cables in the PowerBook series these days.
They can use the some controller chip (i.e.: GEM) in boards that
have different feature sets by using a different PHY. The bulk of
the driver stays the same, but they end up with the desired features.

	Brad Boyer
	flar at

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