Specifications

Product Errata 107
Revision Guide for AMD Family 10h Processors
41322 Rev. 3.84 August 2011
386 HyperTransport™ Link in Retry Mode That Receives Repeated
Invalid Packets May Cause MCA Exception
Description
Under highly specific and detailed internal timing conditions, a HyperTransport™ link in retry mode
that receives repeated invalid packets in a specific sequence may cause the processor to generate a
link data buffer overflow MCA exception.
This erratum applies only when a link is configured as 16-bit ganged and the northbridge current
operating frequency is less than the link clock frequency.
Potential Effect on System
System hang. A link data buffer overflow MCA exception will also be reported.
Suggested Workaround
System software should program the Link Base Channel Buffer Count Registers F0x[F0, D0, B0,
90][27:25] (FreeData) to 000b to disable all free list link data buffers. To maximize system
performance when applying this workaround on NFCM coherent links, system software should
modify the settings for F0x[F0, D0, B0, 90] as specified in the BIOS and Kernel Developer’s Guide
(BKDG) for AMD Family 10h Processors, order# 31116, per the following table:
Fix Planned
Yes
Register/Field NFCM Coherent Link Modified Setting
FreeData 0
FreeCmd 8
RspData 3
NpReqData 2
ProbeCmd 8
RspCmd 9
PReq 3
NpReqCmd 4