User manual

Chapter 3 BIOS Setup
EC7-1817LNAR - 43 -
System Resource Managed by UEFI under X86 Platform
We define three kinds of system resources here: I/O port address, IRQ interrupt
number and DMA number.
 DMA
Level Function
DMA0 Unassigned
DMA1 Unassigned
DMA2 Unassigned
DMA3 Unassigned
DMA4 Used for DMAC cascade
DMA5 Unassigned
DMA6 Unassigned
DMA7 Unassigned
 APIC
Advanced programmable interrupt controller. Most motherboards above P4 level
support APIC and provide more than 16 interrupt sources, like IRQ16 - IRQ23; while
some others can have up to 28 interrupt sources, such as motherboard supporting
PCI-X. However, relevant OS are required to enable that function, and currently, only
the OS above Windows 2000 could support that function.
 IO Port Address
Only 16 IO address lines are designed for X86, from 0 ~ 0FFFFh; there is 64K for the
system I/O address space. In traditional ISA connector, only the foregoing 1024 (0000
~ 03FFh) are adopted while the ports above 0400h are adopted by PCI and EISA
connectors. Each peripheral will occupy portion of the space. The table below shows
parts of the I/O connectors used in X86 platform.