Errata
Specification Update
29
AN34.
Pending x87 FPU Exceptions (#MF) following STI May Be Serviced
before Higher Priority Interrupts
Problem:
Interrupts that are pending prior to the execution of the STI (Set Interrupt Flag)
instruction are serviced immediately after the STI instruction is executed. Because of
this erratum, if following STI, an instruction that triggers a #MF is executed while
STPCLK#, Enhanced Intel SpeedStep® Technology transitions or Intel® Thermal
Monitor 1 events occur, the pending #MF may be serviced before higher priority
interrupts.
Implication:
Software may observe #MF being serviced before higher priority interrupts.
Workaround:
None identified.
Status:
For the steppings affected, see the
AN35.
Programming the Digital Thermal Sensor (DTS) Threshold May Cause
Unexpected Thermal Interrupts
Problem:
Software can enable DTS thermal interrupts by programming the thermal threshold
and setting the respective thermal interrupt enable bit. When programming DTS
value, the previous DTS threshold may be crossed. This will generate an unexpected
thermal interrupt.
Implication:
Software may observe an unexpected thermal interrupt occur after reprogramming
the thermal threshold.
Workaround:
In the ACPI/OS implement a workaround by temporarily disabling the DTS threshold
interrupt before updating the DTS threshold value.
Status:
For the steppings affected, see the
AN36.
Erratum removed
AN37.
The Processor May Report a #TS Instead of a #GP Fault
Problem:
A jump to a busy TSS (Task-State Segment) may cause a #TS (invalid TSS exception)
instead of a #GP fault (general protection exception).
Implication:
Operation systems that access a busy TSS may get invalid TSS fault instead of a #GP
fault. Intel has not observed this erratum with any commercially available software.
Workaround:
None identified.
Status:
