Vol. 3B 15-23

MACHINE-CHECK ARCHITECTURE

15.9.2.6   Memory Controller Errors

The memory controller errors are defined with the 3-bit MMM (memory transaction type), and 4-bit CCCC 
(channel) sub-fields. The encodings for MMM and CCCC are defined in Table 15-14.

15.9.3 

Architecturally Defined UCR Errors 

Software recoverable compound error code are defined in this section.

15.9.3.1   Architecturally Defined SRAO Errors

The following two SRAO errors are architecturally defined. 

•

UCR Errors detected by memory controller scrubbing; and

•

UCR Errors detected during L3 cache (L3) explicit writebacks.

The MCA error code encodings for these two architecturally-defined UCR errors corresponds to sub-classes of 
compound MCA error codes (see Table 15-9). Their values and compound encoding format are given in Table 
15-15. 

Table 15-16 lists values of relevant bit fields of IA32_MCi_STATUS for architecturally defined SRAO errors. 

Table 15-14.  Encodings of MMM and CCCC Sub-Fields 

Sub-Field

Transaction

Mnemonic

Binary Encoding

MMM 

Generic undefined request

GEN

000

Memory read error

RD

001

Memory write error

WR

010

Address/Command Error

AC

011

Memory Scrubbing Error

MS

100

Reserved

101-111

CCCC

Channel number

CHN

0000-1110

Channel not specified

1111

Table 15-15.  MCA Compound Error Code Encoding for SRAO Errors

Type

MCACOD Value MCA Error Code Encoding

1

NOTES:

1. Note that for both of these errors the correction report filtering (F) bit (bit 12) of the MCA error must be ignored. 

Memory Scrubbing 

C0H - CFH

0000_0000_1100_CCCC
000F 0000 1MMM CCCC (Memory Controller Error), where
Memory subfield MMM = 100B (memory scrubbing)
Channel subfield CCCC = channel # or generic

L3 Explicit Writeback 17AH

0000_0001_0111_1010
000F 0001 RRRR TTLL (Cache Hierarchy Error) where
Request subfields RRRR = 0111B (Eviction)
Transaction Type subfields TT = 10B (Generic)
Level subfields LL = 10B 

Table 15-16.  IA32_MCi_STATUS Values for SRAO Errors

SRAO Error

Valid

OVER

UC

EN

MISCV

ADDRV

PCC

S

AR

MCACOD

Memory Scrubbing

1

0

1

x

1

1

1

0

x

1

0

C0H-CFH

L3 Explicit Writeback

1

0

1

x

1

1

1

0

x

1

0

17AH