Xycom AHIP-370, Manual

Page: 17 / 65

Chapter Two - Installation
17
DMA Mapping
Table 2-4. DMA Channels
DMA Function
DMA0 Unused (Could be used for EPP/ECP parallel port option)
DMA1 Unused
DMA2 Floppy Controller
DMA3 Unused (Could be used for EPP/ECP parallel port option)
DMA5 Unused
DMA6 Unused
DMA7 Unused
DMA channels 0-3 are 8-bit and DMA channels 5-7 are 16-bit. When the ECP option
is enabled, one of the 8-bit DMA channels is used.
Memory Map
The following table shows the AHIP-370 memory map. The I/O designation refers to
memory viewed as part of the AT bus.
Table 2- 5. Memory Map
Address Range (HEX) Size Device
FFFE0000 - FFFFFFFF 128K SYSTEM BIOS
end of DRAM - FFFDFFFF xxxK I/O Memory
00100000 - end of DRAM xxxK DRAM*
000F0000 - 000FFFFF 64K SYSTEM BIOS
000E0000 - 000EFFFF 64K SYSTEM BIOS
000D0000 - 000DFFFF 64K AT bus I/O
000C0000 - 000CBFFF 48K VGA BIOS
000A0000 - 000BFFFF 128K VGA DRAM MEMORY
00000000 - 0009FFFF 640K DRAM
*See Intel 430BX data sheet for a description of optional settings for assigning
memory holes or gaps within memory map area.