QG5000XSL9TH Datasheet, PDF (277/458 Pages) Intel Corporation – Intel 5000X Chipset Memory Controller Hub (MCH)

System Address Map
4 System Address Map
The Intel 5000X chipset MCH supports 36 bits of memory address space. Internally
Intel 5000P Chipset carries 40 bits of address into various memory controller
components. The processors designed for Intel 5000P Chipset, support only 36 bits of
memory addressing and 16 bits of addressable I/O space. However internally the MCH
supports 40 bits and several of the MCH memory configuration registers require 40 bit
address programming.
There is a legacy (compatibility) memory address space under the 1-MB region that is
divided into regions that can be individually controlled with programmable attributes
(for example, disable, read/write, write only, or read only). Attribute programming is
described in Chapter 3. The Intel 5000X chipset MCH supports several fixed address
ranges in addition to the compatibility range. These are:
• Compatibility area below 1MB
• Interrupt delivery region
• System region in 32MB just below 4GB
There are several relocatable regions such as the memory mapped I/O region.These
regions are controlled by various programmable registers covered in Chapter 3.
This chapter focuses on how the memory space is partitioned and the uses of the
separate memory regions.
In the following sections, it is assumed that all of the compatibility memory ranges
reside on the ESI/PCI Express/PCI interfaces. VGA address ranges are mapped to PCI
Express address space as well. In the absence of more specific references, cycle
descriptions referencing PCI should be interpreted as the ESI/PCI interface.
The Intel 5000X chipset MCH memory map includes a number of programmable
ranges. All of these ranges must be unique and non-overlapping as shown in
Figure 4-1. There are no hardware interlocks to prevent problems in the case of
overlapping ranges. Accesses to overlapped ranges may produce indeterminate results.
For example, setting HECBASE to all zeros will overlap the MMCFG region and the
compatibility region resulting in unpredictable results.
Intel^® 5000X Chipset Memory Controller Hub (MCH) Datasheet
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