FW: RST# Timing ECN

[Jeff Dahlin <JDahlin@appiangraphics.com>]

> Scott,
> The way that I read this:
> ----------
> "All other devices must be prepared to respond as a target not more
> than the
> Trhfa after the deassertion of RST#.  It is *** RECOMMENDED *** that
> the
> system wait at least Trhfa following the deassertion of RST# to a
> device,
> before the first access to that device, unless the device is in the
> path
> between the CPU and the boot ROM, or the ***SYSTEM KNOWS THAT THE
> DEVICE IS
> READY SOONER.****"
> 
> Is that if there are components on the motherboard, the system can
> know  (or the designer of the systems knows) if the device is ready or
> not.  They can then take advantage of that knowledge and get accesses
> to those devices.  Since everyone else on the bus handles FRAME#s
> correctly after Trhff, writing to devices that are on the motherboard
> and are know to be ready should not cause problems for any add-in
> cards.  
> 
> In any case the way it is written now is ambiguous they do need to
> clarify when Trhfa is a requirement and when it is a recommendation.
> The committee may be trying to leave a loophole so that systems can
> get up and running faster -- it looks like it may be too big of a
> loophole.
> 
> 
> Thanks,
> Jeff Dahlin
> Appian Graphics
> 18047 NE 68th St., Suite B-100
> Redmond, WA  98052
> (425) 882-2020
>  FAX 882-8618
> 
> 
PS, Sorry about two copies Scott, I accidentally sent the first one only
to you.  -JJD