Errata
64
Specification
Update
93.
Machine Check Exceptions May not Update Last-Exception Record
MSRs (LERs)
Problem:
The Last-Exception Record MSRs (LERs) may not get updated when Machine Check
Exceptions occur.
Implication:
When this erratum occurs, the LER may not contain information relating to the
machine check exception. They will contain information relating to the exception prior
to the machine check exception.
Workaround:
None identified.
Status:
For the steppings affected, see the
Summary Tables of Changes.
94.
Stores to Page Tables May Not Be Visible to Pagewalks for
Subsequent Loads without Serializing or Invalidating the Page Table
Entry
Problem:
Under rare timing circumstances, a page table load on behalf of a programmatically
younger memory access may not get data from a programmatically older store to the
page table entry if there is not a fencing operation or page translation invalidate
operation between the store and the younger memory access. Refer to the
IA-32
Intel
®
Architecture Software Developer's Manual
for the correct way to update page
tables. Software that conforms to the Software Developer's Manual will operate
correctly.
Implication:
If the guidelines in the Software Developer's Manual are not followed, stale data may
be loaded into the processor's Translation Lookaside Buffer (TLB) and used for
memory operations. This erratum has not been observed with any commercially
available software.
Workaround:
The guidelines in the IA-32
Intel
®
Architecture Software Developer's Manual
should be followed.
Status:
For the steppings affected, see the
Summary Tables of Changes.
95.
A Timing Marginality in the Arithmetic Logic Unit (ALU) May Cause
Indeterminate Behavior
Problem:
A timing marginality may exist in the clocking of the ALU which leads to a slowdown
in the speed of the circuit’s operation. This could lead to incorrect behavior of the
ALU.
Implication:
When this erratum occurs, unpredictable application behavior and/or system hang
may occur.
Workaround:
It is possible for the BIOS to contain a workaround for this erratum.
Status:
For the steppings affected, see the
Summary Tables of Changes.