30
Specification Update
BJ32.
Values for LBR/BTS/BTM Will be Incorrect after an Exit from SMM
Problem:
After a return from SMM (System Management Mode), the CPU will incorrectly update
the LBR (Last Branch Record) and the BTS (Branch Trace Store), hence rendering their
data invalid. The corresponding data if sent out as a BTM on the system bus will also be
incorrect. Note: This issue would only occur when one of the 3 above mentioned debug
support facilities are used.
Implication:
The value of the LBR, BTS, and BTM immediately after an RSM operation should not be
used.
Workaround:
None identified.
Status:
For the steppings affected, see the Summary Tables of Changes.
BJ33.
Unsupported PCIe* Upstream Access May Complete with an Incorrect
Byte Count
Problem:
PCIe* Upstream IO and Configuration accesses are not supported. If an IO or
Configuration request is received upstream, the integrated PCIe controller will treat it
as an unsupported request, the request will be dropped, and a completion will be sent
with the UR (Unsupported Request) completion status. This completion, according to
the PCIe specification, should indicate a byte count of 4. Due to this erratum, the byte
count is set to the same byte count as the offending request.
Implication:
The processor response to an unsupported PCIe access may not fully comply to the
PCIe specification.
Workaround:
PCIe agents should not issue unsupported accesses.
Status:
For the steppings affected, see the Summary Tables of Changes.
BJ34.
Malformed PCIe* Transactions May be Treated as Unsupported
Requests Instead of as Critical Errors
Problem:
PCIe MSG/MSG_D TLPs (Transaction Layer Packets) with incorrect Routing Code as well
as the deprecated TCfgRD and TCfgWr types should be treated as malformed
transactions leading to a critical error. Due to this erratum, the integrated PCIe
controller's root ports may treat such messages as UR (Unsupported Requests).
Implication:
Legacy malformed PCIe transactions may be treated as UR instead of as critical errors.
Workaround:
None identified.
Status:
For the steppings affected, see the Summary Tables of Changes.
Summary of Contents for BX80623G530
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