ADWPCIXRSKU20 Intel, ADWPCIXRSKU20 Datasheet - Page 60

• Manufacturer Part Number: ADWPCIXRSKU20
• Manufacturer: Intel

Specifications of ADWPCIXRSKU20

• Lead Free Status / Rohs Status: Supplier Unconfirmed

Functional Architecture
3.5.1.2.2
Memory addresses below the 4GB range are mapped to the PCI bus. This region is divided into
three sections: High BIOS, APIC configuration space, and general-purpose PCI memory. The
General-purpose PCI memory area is typically used memory-mapped I/O to PCI devices. The
memory address space for each device is set using PCI configuration registers.
3.5.1.2.3
The top 1MB of extended memory under 4GB is reserved for the system BIOS, extended BIOS
for PCI devices, and A20 aliasing by the system BIOS. The lntel® Xeon™ processor begins
executing from the high BIOS region after reset.
3.5.1.2.4
The BIOS creates a region immediately below 4 GB to accommodate memory-mapped I/O
regions for the system BIOS Flash, APIC memory and 32-bit PCI devices. Any system memory
in this region is remapped above 4GB.
3.5.1.2.5
A 64KB block located 20MB below 4GB (0FEC00000 to 0FEC0FFFFh) is reserved for the I/O
APIC configuration space. The first I/O APIC is located at FEC00000h. The second I/O APIC is
located at FEC80000h. The third I/O APIC is located at FEC80100h.
3.5.1.2.6
An lntel® Xeon™ processor based system can have up to 64 GB of addressable memory. With
the chipset only supporting 16GB of addressable memory, the BIOS uses an extended
addressing mechanism to use the address ranges.
3.5.1.3
System BIOS and option ROM can be shadowed in main memory. Typically this is done to allow
ROM code to execute more rapidly out of RAM. ROM is designated read-only during the copy
process while RAM at the same address is designated write-only. After copying, the RAM is
designated read-only. After the BIOS is shadowed, the attributes for that memory area are set to
read only so that all writes are forwarded to the expansion bus.
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PCI Memory Space
High BIOS
High Memory Gap Reclaiming
I/O APIC Configuration Space
Extended lntel
Memory Shadowing
®
Xeon™ Processor Region (above 4GB)
Intel order number C91056-002
Intel® Server Board SE7320VP2
Revision 2.1