Intel Xeon® Processor X3430 (8M Cache, 2.40 GHz) BX80605X3430 User Manual

Product codes
BX80605X3430
Page of 296
System Address Map
274
Intel® Xeon® Processor 3400 Series Datasheet, Volume 2
5.2.2
System DRAM Memory Regions
These address ranges are always mapped to system DRAM memory, regardless of the 
system configuration. The top of main memory below 4 GB is defined by the Top of Low 
Memory (TOLM). Memory between 4 GB and TOHM is extended system memory. Since 
the platform may contain multiple processors, the memory space is divided amongst 
the processors. There may be memory holes between each processor’s memory 
regions. These system memory regions are either coherent or non-coherent. A set of 
range registers in the IIO define a non-coherent memory region 
(NcMem.Base/NcMem.Limit) within the system DRAM memory region shown above. 
System DRAM memory region outside of this range but within the DRAM region shown 
in table above is considered coherent.
For inbound transactions, IIO positively decodes these ranges using a couple of 
software programmable range registers. Refer to 
 for details of inbound 
decoding towards system memory. For outbound transactions, it would be an error for 
IIO to receive non-coherent accesses to these addresses from Intel QuickPath 
Interconnect, but IIO does not explicitly check for this error condition but would rather 
forward such accesses to the subtractive decode port, if one exists downstream, by 
virtue of subtractive decoding, else it is master aborted. Refer to 
further details.
Address Region
From
To
640-KB MS-DOS* Memory
000_0000_0000h
000_0009_FFFFh
1 MB to Top-of-Low-Memory
000_0010_0000h
TOLM
Bottom-of-High-Memory to Top-of-
High-Memory
4 GB
TOHM