Update

R
12 Specification Update
7.
A4, B4 – AGP PCI Write to System Memory May Be Corrupted
Problem: Display corruption or a system hang may result if an upstream AGP FRAME#-based PCI write crosses
a 32-byte aligned boundary. Note that upstream AGP FRAME#-based PCI writes which cross a 32-byte
aligned boundary are expected to be rare.
Implication: The issue may cause display corruption or a system hang. With the workaround implemented, Intel has
done extensive validation and expects less than 3% impact on system performance.
Workaround: A BIOS workaround is available which disconnects upstream AGP FRAME#-based PCI writes to
system memory at 32-byte aligned boundaries. Please refer to your Intel representative for BIOS
workaround details.
Status: There are no plans to fix this erratum in silicon. For steppings affected, see the Summary Tables o
Changes.
8. Mobile Intel® 855GM/855GME Express Chipset SMRAM D_CLS Bit Erratum
Problem: Data and Stack which resides in Extended SMRAM (TSEG/HSEG) is inaccessible if D_CLS bit (Bus 0,
Device 0, Function 0, Register 60h, bit 5) is set.
Implication: May result in a system hang..
Workaround: See Intel® 852GM/855GM/855GME/852GME/852PM/852GMV BIOS Spec Update Rev 2.1 or later.
Status: No Fix. For steppings affected, see the Summary Table of Changes.
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