HP kp721av Manuale Utente
4-8
www.hp.com
Technical Reference Guide
System Support
NOTES:
[1] SFF and CMT only
[1] SFF and CMT only
[2] CMT only
The PCI interrupts can be configured by PCI Configuration Registers 60h..63h to share the
standard ISA interrupts (IRQn).
standard ISA interrupts (IRQn).
✎
The APIC mode is supported by Windows NT, Windows 2000, and Windows XP, and Windows
Vista operating systems. Systems running the Windows 95 or 98 operating system will need to
run in 8259 mode.
Vista operating systems. Systems running the Windows 95 or 98 operating system will need to
run in 8259 mode.
4.3.2 Direct Memory Access
Direct Memory Access (DMA) is a method by which a device accesses system memory without
involving the microprocessor. Although the DMA method has been traditionally used to transfer
blocks of data to or from an ISA I/O device, PCI devices may also use DMA operation as well.
The DMA method reduces the amount of CPU interactions with memory, freeing the CPU for
other processing tasks. For detailed information regarding DMA operation, refer to the data
manual for the Intel 82801 ICH10 I/O Controller Hub.
involving the microprocessor. Although the DMA method has been traditionally used to transfer
blocks of data to or from an ISA I/O device, PCI devices may also use DMA operation as well.
The DMA method reduces the amount of CPU interactions with memory, freeing the CPU for
other processing tasks. For detailed information regarding DMA operation, refer to the data
manual for the Intel 82801 ICH10 I/O Controller Hub.
Table 4-5.
PCI Interrupt Distribution
System Interrupts
System Board
Connector
PIRQ
A
PIRQ
B
PIRQ
C
PIRQ
D
PIRQ
E
PIRQ
F
PIRQ
G
PIRQ
H
PCI slot 1 (J20) [1]
A
B
C
D
PCI slot 2 (J21) [1]
D
A
B
C
PCI slot 3 (J22) [2]
C
D
A
B