Datasheet
Processor Configuration Registers
Intel
®
 Xeon
®
 and Intel
®
 Core™ Processors For Communications Infrastructure
May 2012 Datasheet - Volume 1 of 2
Document Number: 327405
-001 159
Size: 32 bits
BIOS Optimal Default 00h
This register defines channel characteristics - number of DIMMs, number of ranks, size, 
ECC, interleave options and ECC options.
Table 11-11.Address Decode Channel 0
Bit Access
Default 
Value
RST/
PWR
Description
31:26  RO  0h  Reserved (RSVD) 
25:24  RW-L  00b  Uncore
ECC is active in the channel (ECC): 
00 =no ECC active in the channel 
01 =ECC is active in IO, ECC logic is not active In this 
case, on write accesses the data driven on ECC 
byte is copied from DQ 7:0 (to be used in training 
or IOSAV) 
10 =ECC is disabled in IO, but ECC logic is enabled (to 
be used in ECC4ANA mode) 
11 =ECC active in both IO and ECC logic 
23:23  RO  0h  Reserved (RSVD) 
22  RW-L  1b  Uncore
Enhanced Interleave mode (Enh_Interleave): 
0 = off 
1 = on
21  RW-L  1b  Uncore
Rank Interleave (RI): 
Rank Interleave 
0 = off 
1 = on
20  RW-L  0b  Uncore
DIMM B DDR width (DBW): 
DIMM B width of DDR chips 
0 = X8 chips 
1 = X16 chips 
19  RW-L  0b  Uncore
DIMM A DDR width (DAW): 
DIMM A width of DDR chips 
0 = X8 chips 
1 = X16 chips 
18  RW-L  0b  Uncore 
DIMM B number of ranks (DBNOR): 
0 = single rank 
1 = dual rank 
17  RW-L  0b  Uncore 
DIMM A number of ranks (DANOR):
0 = single rank 
1 = dual rank 
16  RW-L  0b  Uncore 
DIMM A select (DAS): 
Selects which of the DIMMs is DIMM A - should be the 
larger DIMM:
0 - DIMM 0
1 - DIMM 1
15:8  RW-L  00h Uncore 
Size of DIMM B (DIMM_B_Size):
Size of DIMM B 256 MB multiples
7:0  RW-L  00h  Uncore 
Size of DIMM A (DIMM_A_Size):
Size of DIMM A 256 MB multiples










