Technical Reference; Introduction; Memory Resources; Addressable Memory - Intel BLKD915PGNL - LGA775 800FSB 4DDR Audio Lan SATA ATX 4PCI Technical Product Specification

2 Technical Reference

What This Chapter Contains
2.1

Introduction .................................................................................................................. 55

2.2

Memory Resources ...................................................................................................... 55

2.3 DMA Channels ............................................................................................................. 57
2.4 Fixed I/O Map............................................................................................................... 58
2.5 PCI Configuration Space Map...................................................................................... 59
2.6 Interrupts ...................................................................................................................... 60
2.7 PCI Conventional Interrupt Routing Map ..................................................................... 61
2.8 Connectors................................................................................................................... 63
2.9 Jumper Block ............................................................................................................... 77
2.10 Mechanical Considerations .......................................................................................... 78
2.11 Electrical Considerations.............................................................................................. 81
2.12 Thermal Considerations ............................................................................................... 83
2.13 Reliability...................................................................................................................... 85
2.14 Environmental .............................................................................................................. 86
2.15 Regulatory Compliance................................................................................................ 87
2.1 Introduction
Sections 2.2 - 2.6 contain several standalone tables. Table 12 describes the system memory map,
Table 13 lists the DMA channels, Table 14 shows the I/O map, Table 15 defines the PCI
Conventional bus configuration space map, and Table 16 describes the interrupts. The remaining
sections in this chapter are introduced by text found with their respective section headings.
2.2 Memory Resources

2.2.1 Addressable Memory

The board utilizes 4 GB of addressable system memory. Typically the address space that is
allocated for PCI Conventional bus add-in cards, PCI Express configuration space, BIOS (firmware
hub), and chipset overhead resides above the top of DRAM (total system memory). On a system
that has 4 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/firmware hub (2 MB)
•
Local APIC (19 MB)
•
Digital Media Interface (40 MB)
•
Front side bus interrupts (17 MB)
•
PCI Express configuration space (256 MB)
•
MCH base address registers, internal graphics ranges, PCI Express ports (up to 512 MB)
•
Memory-mapped I/O that is dynamically allocated for PCI Conventional and PCI Express
add-in cards
55