Specification Update

Errata
82 Specification Update
W120. A Thermal Interrupt Is Not Generated When the Current
Temperature Is Invalid
Problem: When the DTS (Digital Thermal Sensor) crosses one of its programmed
thresholds it generates an interrupt and logs the event
(IA32_THERM_STATUS MSR (019Ch) bits [9, 7]). Due to this erratum,
if the DTS reaches an invalid temperature (as indicated
IA32_THERM_STATUS MSR bit[31]) it does not generate an interrupt
even if one of the programmed thresholds is crossed and the
corresponding log bits become set.
Implication: When the temperature reaches an invalid temperature the CPU does
not generate a Thermal interrupt even if a programmed threshold is
crossed.
Workaround: None identified.
Status: For the steppings affected, see the Summary Tables of Changes.
W121. CMPSB, LODSB, or SCASB in 64-bit Mode with Count Greater
or Equal to 2
48
May Terminate Early
Problem: In 64-bit Mode CMPSB, LODSB, or SCASB executed with a repeat prefix
and count greater than or equal to 2
48
may terminate early. Early
termination may result in one of the following.
• The last iteration not being executed
• Signaling of a canonical limit fault (#GP) on the last iteration
Implication: While in 64-bit mode, with count greater or equal to 2
48
, repeat string
operations CMPSB, LODSB or SCASB may terminate without completing
the last iteration. Intel has not observed this erratum with any
commercially available software.
Workaround: Do not use repeated string operations with RCX greater than or equal to 2
48
.
Status: For the steppings affected, see the Summary Tables of Changes.
W122. Returning to Real Mode from SMM with EFLAGS.VM Set May
Result in Unpredictable System Behavior
Problem: Returning back from SMM mode into real mode while EFLAGS.VM is set in
SMRAM may result in unpredictable system behavior.
Implication: If SMM software changes the values of the EFLAGS.VM in SMRAM, it
may result in unpredictable system behavior. Intel has not observed
this behavior in commercially available software.
Workaround: SMM software should not change the value of EFLAGS.VM in SMRAM.
Status: For the steppings affected, see the Summary Tables of Changes.