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Chapter 4
HP BIOS
BIOS Addresses
DMA Channel Controllers
Only “I/O-to-memory” and “memory-to-I/O” transfers are allowed. “I/O-to-I/O” and
“memory-to-memory” transfers are disallowed by the hardware configuration. The system
controller supports seven DMA channels, each with a page register used to extend the
addressing range of the channel to 16 MB. The following table summarizes how the DMA
channels are allocated.
0778 - 077B
LPT1 ECP
0CF8 - 0CFF
PCI configuration space
8000 -
PIIX4E Power Management I/O Space
8400 -
NS317 ACPI Registers
8800 -
PIIX4E SMBus I/O Space
Table 4-5. Summary Of How The DMA Channels Are Allocated
DMA controller
Channel
Function
DMA 0
AD1816 Capture
DMA 1
AD1816 Playback
DMA 2
NS317 Flexible disk controller
DMA 3
NS317 LPT ECP
DMA 4
Used to cascade DMA channels 0-3
DMA 5
Free
DMA 6
Free
DMA 7
Free
Table 4-4. HP I/O Port Map
Default Values for
I/O Address Ports
Function
Содержание X Class 500/550MHz
Страница 6: ...6 Contents ...
Страница 8: ...8 Figures ...
Страница 15: ...15 1 System Overview ...
Страница 66: ...66 Chapter2 System Board Devices on the ISA Bus ...
Страница 96: ...96 Chapter3 Interface Boards and Mass Storage Drivers Connectors and Sockets ...
Страница 134: ...134 Chapter5 Tests and Error Messages Beep Codes ...
Страница 135: ...135 A Regulatory Information and Warranty ...
Страница 146: ...146 AppendixA Regulatory Information and Warranty HP Hardware Warranty ...