82US15W Datasheet, PDF (18/22 Pages) Intel Corporation – Intel® System Controller Hub

Errata
24.
PCI Express* Unaligned Memory Read Data Corruption
Problem:
The Byte Enable (BE) field in a PCI Express* (PCIe*) transaction is invalid when an
unaligned memory read transaction is performed on the PCIe* memory mapped I/O
(MMIO) device space. F or reads that cross the DWORD boundary, the first BE field
incorrectly matches the last BE field instead of being the complement for a proper data
read (e.g., BE fields for a four byte read results in 0011b and 0011b instead of 0011b
and 1100b.)
Implication: Reads from the MMIO space that crosses the DWORD boundary causes data corruption.
Workaround:None.
Status:
For the steppings affected, see the Summary Tables of Changes.
25.
USB Client High Speed Termination Delay
Problem:
Intel® SCH as a USB client waits to disconnect the D+ pull-up resistor until the host
stops transmitting the Chirp JKJKJK sequence to identify the client as a high speed USB
device.
Implication: Potential violation of USB 2.0 Client Specification, as the USB client should disconnect
the D+ pull-up resistor and send back a Chirp K within 500 uSec of receiving the Chirp
JKJKJK sequence from the USB host.
Workaround:None. USB 2.0 compliance may be obtained via waiver given that validation of behavior
does not impact host recognition of high speed USB client.
Status:
For the steppings affected, see the Summary Tables of Changes.
26.
USB Audio Device Underrun/Overrun
Problem:
During the transition from C3 or C4 state to C2 (C2 pop-up time), USB classic mode
can lead to underrun/overrun situation while performing an isochronous transaction
(e.g., video/audio streaming).
Implication: Platforms requiring isochronous transactions on USB classic mode could show transient
transfer errors.
Workaround:None. Adjust the MTH register to lengthen the wait time entering C3/C4 state, or
attach the device through a USB 2.0 hub to Intel® SCH.
Status:
For the steppings affected, see the Summary Tables of Changes.
18
Specification Update