Intel E7-8891 v2 CM8063601377422 Manual Do Utilizador

Intel

®

 Xeon

® 

Processor E7-2800/4800/8800 v2 Product Family

155

Datasheet Volume Two: Functional Description, February 2014

For lock-step channel configuration, only one x8 device can be tagged per rank-pair. 
SMM software must copy the faildevice log from Channel 0/2 to the corresponding 
register in Channel 1/3, then set EN for both channels in lockstepped pair. 

There is no hardware logic to report incorrect programming error. Unpredictable error 
and / or silent data corruption will be the consequence of such programming error. 

If the rank-sparing is enabled, it is recommended to prioritize the rank-sparing before 
triggering the device tagging due to the nature of the device tagging would drop the 
correction capability and any subsequent ECC error from this rank would cause 
uncorrectable error. 

The Home Agent is responsible for memory transactions and interacts with the 
processor’s ring and handles incoming and outgoing transactions. 

7:7

RWS_LB

0x0

Device tagging enable for this rank (en):

Device tagging (SDDC) enable for this rank. Once set, the parity device of 

the rank is used for the replacement device content. After tagging, the rank 

will no longer have the “correction” capability. ECC error “detection” 

capability will not degrade after setting this bit.
Warning: For DDR3 lock-step channel configuration, only one x8 device can 

be tagged per rank-pair. SMM software must copy the faildevice log from 

Channel 0/2 to the corresponding register in Channel 1/3, then set EN for 

both channels in lockstepped pair.
Must never be enable prior using IOSAV
DDDC:
On DDDC supported systems, BIOS has the option to enable SDDC in 

conjunction with DDDC_CNTL:SPARING to enable faster sparing with SDDC 

substitution. This field is cleared by HW on completion of DDDC sparing.

6:6

RV

-

Reserved.

5:0

RWS_V

0x3f

Fail Device ID for this rank (faildevice):

Hardware will capture the fail device ID of the rank in the FailDevice field 

upon successful correction from the device correction engine. After SDDC is 

enabled HW may not update this field. 
In DDR3 lockstep mode, the faildevice will only be logged by hardware on 

Channel 0/2 of lockstepped pair. SMM must copy faildevice to the other 

lockstepped channel before enabling SDDC.

Native DDR/VMSE2:1/VMSE1:1x8:
Valid Range is decimal 0-17 to indicate which x4 device (independent 

channel) or x8 device (lock-step mode) has failed. 

VMSE1:1x4 (DDDC):
Valid Range is decimal 0-35 to indicate which x4 device has failed.

Note that when DDDC has been enabled on the nonspare device, and a 

subsequent failure of the spare device occurs, the value logged here will be 

equal to the DDDC faildevice.
Since the device tagging should not be enabled at first boot, the default 

value in this field is chosen to be out of the range.