Specification Update

Errata
24 Specification Update
AN18. Erratum removed
AN19. Erratum removed
AN20. LOCK# Asserted during a Special Cycle Shutdown Transaction May
Unexpectedly Deassert
Problem: During a processor shutdown transaction, when LOCK# is asserted and if a DEFER# is
received during a snoop phase and the Locked transaction is pipelined on the front
side bus (FSB), LOCK# may unexpectedly deassert.
Implication: When this erratum occurs, the system may hang during shutdown. Intel has not
observed this erratum with any commercially available systems or software.
Workaround: None identified.
Status: For the steppings affected, see the Summary Tables of Changes
.
AN21. Erratum removed.
AN22. Last Branch Records (LBR) Updates May Be Incorrect after a Task
Switch
Problem: A Task-State Segment (TSS) task switch may incorrectly set the LBR_FROM value to
the LBR_TO value.
Implication: The LBR_FROM will have the incorrect address of the Branch Instruction.
Workaround: None identified.
Status: For the steppings affected, see the Summary Tables of Changes
.
AN23. Address Reported By Machine-Check Architecture (MCA) on Single-bit
L2 ECC Errors May Be Incorrect
Problem: When correctable single-bit ECC errors occur in the L2 cache the address is logged in
the MCA address register (MCi_ADDR). Under some scenarios, the address reported
may be incorrect.
Implication: Software should not rely on the value reported in MCi_ADDR, for Single-bit L2 ECC
errors
Workaround: None identified.
Status: For the steppings affected, see the Summary Tables of Changes
.