Intel NUC Kit NUC5PGYH, Technical Product Specification

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2 Technical Reference
2.1 Memory Resources
2.1.1 Addressable Memory
The board utilizes up to 8 GB of addressable system memory. Typically the address space that is
allocated for PCI Conventional bus add-in cards, PCI Express configuration space, BIOS (SPI Flash
device), and chipset overhead resides above the top of DRAM (total system memory). On a system
that has 8 GB of system memory installed, it is not possible to use all of the installed memory due
to system address space being allocated for other system critical functions. These functions
include the following:
•
BIOS/SPI Flash device (64 Mbit)
• Local APIC (19 MB)
• Direct Media Interface (40 MB)
•
PCI Express configuration space (256 MB)
•
SoC base address registers PCI Express ports (up to 256 MB)
• Memory-mapped I/O (I/O fabric) that is dynamically allocated for PCI Express add-in cards
(256 MB)
The board provides the capability to reclaim the physical memory overlapped by the memory
mapped I/O logical address space. The board remaps physical memory from the top of usable
DRAM boundary to the 4 GB boundary to an equivalent sized logical address range located just
above the 4 GB boundary. All installed system memory can be used when there is no overlap of
system addresses.
2.2 Connectors and Headers
CAUTION
Only the following connectors and headers have overcurrent protection: back panel and front
panel USB.
This section describes the board’s connectors and headers. The connectors and headers can be
divided into these groups:
• Front panel I/O connector
•
Back panel I/O connectors