Datasheet

Errata
48 Specification Update
AH18. Writing Shared Unaligned Data that Crosses a Cache Line without
Proper Semaphores or Barriers May Expose a Memory Ordering Issue
Problem: Software which is written so that multiple agents can modify the same shared
unaligned memory location at the same time may experience a memory ordering
issue if multiple loads access this shared data shortly thereafter. Exposure to this
problem requires the use of a data write which spans a cache line boundary.
Implication: This erratum may cause loads to be observed out of order. Intel has not observed this
erratum with any commercially available software or system.
Workaround: Software should ensure at least one of the following is true when modifying shared
data by multiple agents:
 The shared data is aligned.
 Proper semaphores or barriers are used in order to prevent concurrent data
accesses.
Status: For the steppings affected, see the Summary Tables of Changes.
AH19. Code Segment Limit Violation May Occur On 4-Gigabyte Limit Check
Problem: Code Segment limit violation may occur on 4-Gigabyte limit check when the code
stream wraps around in a way that one instruction ends at the last byte of the
segment and the next instruction begins at 0x0.
Implication: This is a rare condition that may result in a system hang. Intel has not observed this
erratum with any commercially available software, or system.
Workaround: Avoid code that wraps around segment limit.
Status: For the steppings affected, see the Summary Tables of Changes.