Specifications

System BIOS and Resources
System Resources
Chapter 4 67
DMA Channel Controllers
The system permits only I/O-to-memory and memory-to-I/O transfers.
The hardware configuration doesn’t allow I/O-to-I/O or
memory-to-memory transfers.
The system controller supports seven DMA channels, each with a page
register that extends the channel’s addressing range to 16MB.
The following table shows how the system allocates DMA channels.
C000 - Power management I/O space and ACPI
registers
C100 - C10F SMBus I/O space
DMA controller
Channel Function
DMA 0 Free
DMA 1 Free if not used for parallel port in Setup
DMA 2 Floppy disk drive controller
DMA 3 Free if not used for parallel port in Setup
DMA 4 Used to cascade DMA channels 0-3
DMA 5 Free
DMA 6 Free
DMA 7 Free
Default Values for
I/O Address Ports
Function