Errata - Intel 6 SERIES CHIPSET - SPECIFICATION UPDATE 01-2011 Specification

Errata

1. USB Isoch In Transfer Error Issue
Problem: If a USB Full-Speed inbound isochronous transaction with a packet length 190 bytes or
greater is started near the end of a micro-frame the PCH may see more than 189 bytes
in the next micro-frame.
Implication: If the PCH sees more than 189 bytes for a micro-frame an error will be sent to software
and the isochronous tr ansfer will be lost. If a single data pack et is lost no perce ptible
impact for the end user is expected.
Note:
Intel has only observed the issue in a synthetic test environment where precise control
of packet scheduling is available, and has not observed this failure in its compatibility
validation testing.
• Isochronous traffic is periodic and cannot be retried thus it is considered good
practice for software to schedule isochronous transactions to start at the beginning
of a micro-frame. Known software solutions follow this practice.
• To sensitize the system to the issue additional traffic such as other isochronous
transactions or retries of asynchronous transactions would be required to push the
inbound isochronous transaction to the end of the micro-frame.
Workaround: None.
Status: No Plan to Fix.
2. USB Full-Speed / Low-Speed Device Removal Issue
Problem: If two or more USB Full-Speed / Low-Speed devices are co nnected to the same USB
controller, the devices are n ot suspended, and one device is removed, one or more of
the devices remaining in the system may be affected by the disconnect.
Implication: The implication is device de pendent. A device ma y experie nce a delayed transaction,
stall and be reco vered via software, or stall and r equire a reset such as a hot plug to
resume normal functionality.
Workaround: None.
Status: No Plan to Fix.
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Errata
Specification Update