Chapter 3 BIOS Setup
CPC-3813CLD3N
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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.
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
the I/O connectors used in X86 platform.
