Hi,

In a conference call with a SATA chipset manufacturer earlier this week the manufacturer expressed difficulties in the implementation of SATA Asynchronous Notification (AN) because of the perceived lack of clarity in the handling of sleep mode in combination with AN. As the manufacturer is not present on this reflector or the Mt Fuji committee, I am relaying their issue. However the chipset manufacturer is working with device manufacturer(s) from Mt Fuji committee and expect that member(s) will be familiar and supportive of the issue resolution.

The chipset manufacturer is not clear what is the specified device behavior when the host issues a START/STOP UNIT command with parameters to request sleep mode.

The first set of questions is regarding the entry to sleep mode. Should a power state notification be generated? If a power state notification is generated, should AN be set? If a notification is generated and AN is set, will the device complete GESN from the host despite been in sleep mode? Does setting the immediate bit change the behavior of event notification?

The second set of questions is regarding notification while in sleep mode. In sleep mode, can the user insert an optical media? If the user can, can the device generate a media arrival event? If so, can AN be posted and will the device complete GESN from the host despite been in sleep mode?

If the user can insert a media but the device cannot generate a media arrival event, the manufacturer is concerned by the user experience.

If the user cannot insert a media – for instance if the device is actually powered off in sleep and the door won’t open – can PC vendors really use this mode for power saving without affecting the user experience?

Microsoft’s (not speaking on the manufacturer’s behalf now) understanding of the current Mt Fuji specification is that no event is generated *after* entering sleep mode. So if the host issues a START/STOP UNIT command with parameters to request sleep mode with immediate bit set, the command completes, no event is generated and no command but reset will work after the START/STOP UNIT command completes.

But if the host issues a START/STOP UNIT command with parameters to request sleep mode with immediate bit NOT set, the command completes right away, no power event is posted BUT if a GESN command is still processed while entering sleep mode, Power Status Field is set to “4h – Sleep – The device is about to enter sleep state”, and AN is not set.

Microsoft’s understanding of the device sleep power mode is that it should be used only if the host itself (sleeps or) hibernates or powers off. Device sleep power mode should not be used while the host system is active, even if there is no optical device activity, because user interaction with the device would not work in sleep power mode (such as opening / closing the tray, inserting & detection a new media). Instead, standby power mode needs to be used when the host is active but the device is waiting.

Chipset manufacturer measured however that there is a non-negligible power consumption saving by entering sleep mode in comparison to standby mode.

Could the device manufacturers on the reflector help clarify the source of the power consumption in standby mode. What could we do to avoid this power consumption but still preserve the user experience of opening/closing door and detecting inserted media?

With regards,

David Burg.