Intel Pentium 4 Processor on 90 nm Process

Errata
R
72 Intel
®
Pentium
®
4 Processor on 90 nm Process Specification Update
R121. The IA32_MC0_STATUS and IA32_MC1_STATUS Overflow Bit is not set
when Multiple Un-correctable Machine Check Errors Occur at the Same
Time
Problem: When two enabled MC0/MC1 un-correctable machine check errors are detected in the same bank
in the same internal clock cycle, the highest priority error will be logged in IA32_MC0_STATUS
/ IA32_MC1_STATUS register, but the overflow bit may not be set.
Implication: The highest priority error will be logged and signaled if enabled, but the overflow bit in the
IA32_MC0_STATUS/ IA32_MC1_STATUS register may not be set.
Workaround: None identified.
Status: For the steppings affected, see the Summary Tables of Changes.
R122. Debug Status Register (DR6) Breakpoint Condition Detected Flags May be
set Incorrectly
Problem: The Debug Status Register (DR6) may report detection of a spurious breakpoint condition under
certain boundary conditions when either:
• A "MOV SS" or "POP SS" instruction is immediately followed by a hardware debugger
breakpoint instruction, or
• Any debug register access ("MOV DRx, r32" or "MOV r32, DRx") results in a general-detect
exception condition.
Implication: Due to this erratum the breakpoint condition detected flags may be set incorrectly.
Workaround: None identified.
Status: For the steppings affected, see the Summary Tables of Changes.
R123. A Continuous Loop Executing Bus Lock Transactions on One Logical
Processor may Prevent Another Logical Processor from Acquiring
Resources
Problem: In a system supporting Hyper-Threading Technology, when one hardware thread is in a
continuous loop executing bus locks plus other traffic, the other hardware thread may be
prevented from acquiring resources to also execute a lock.
Implication: This erratum may cause system hang or unpredictable system behavior. This erratum has not been
observed with commercially available software.
Workaround: None identified.
Status: For the steppings affected, see the Summary Tables of Changes.
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