Mainboard detail -- what is "SMI" switch?

[Martha H Adams]

I'm installing a VIA EPMA ATX mainboard into an ATX box. It turns
out, the board maker and the box maker have slightly different ideas
about a few details. All the box's panel leads connect to a single
plug connector which doesn't fit the board. So I need to replace that
one plug connector with apparently four smaller ones. I have no
problem with this, except a detail.

Namely, according to the board manual's Front Panel Connectors page,
the board's panel connector includes two terminals for a green LED.
OK, an LED. And two terminals labelled "Green switch" which connects to
ground and SMI. Not OK: normally open or closed? And, *what is* SMI?

Careful reading through the English part of the board manual finds no
other reference in it to "SMI" nor words "S... M... I...".

So I find an "SMI" entry in my Scott Mueller, 15th ed, where it refers
to "System Management Interface." For some older 386 chip versions.
There, it relates to power management; but going back to my board
manual a closer look at possibly relevant parts of it turns up no SMI.

So there's that "Green LED" and "Green switch" and "SMI" and I think
it's real good practical practice, to know what these things are and
what they do. Before I power up this thing for its first smoke test.

But I can't find that information. Help!

Thanks -- Martha Adams

 

[Harry]

Taken from my ASUS A7V333 mobo manual:

The SMI is the System Management Interrupt connection.

It allows the system to be placed into "Green" mode, in which the
system activity is instantly decreased to save power.

HTH

Harry