Dma Channel Controllers; Interrupt Controllers - HP Brio BA300 Technical Reference Manual

BIOS overview

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.
Channel
0
1
2
3
4
5
6
7

interrupt controllers

The Interrupt Requests (IRQ) are numbered sequentially, starting with the master controller, and
followed by the slave.
IRQ
(Interrupt Vector)
INTR
IRQ0
IRQ1
IRQ3
IRQ4
IRQ5
IRQ6
IRQ7
IRQ8
IRQ9
IRQ10
IRQ11
IRQ12
IRQ13
IRQ14
IRQ15
28
DMA controller
Function
Free
Free if not used for parallel port in Setup
Free
Free if not used for parallel port in Setup
Used to cascade DMA channels 0-3
Free
Free
Free
Interrupt Request Description
System Timer
Keyboard Controller
Available (PCI, audio, LAN)
Used by serial port if enabled - COM1
Available (PCI, audio, LAN)
Floppy
LPT1
RTC
On board USB Controller, SCI ACPI, audio, PCI slots
VGA
Available (PCI, audio, LAN)
Mouse
Coprocessor
IDE Primary channel
IDE Secondary channel. Free unless disabled