IBM 6275 - PC 300 GL, Technical Information Manual

Page: 78 / 88

Appendix B. System Address Maps
DMA I/O Address Map
The following figure lists resource assignments for the DMA address map. Any addresses that are not
shown are reserved.
Figure 49 (Page 3 of 3). I/O Address Map
Address (Hex) Size Description
0F40–0F47 8 bytes Windows sound system (if present)
0F86–0F87 2 bytes Available
7000–700D 14 bytes SMBus I/O space registers
8000–8037 56 bytes Power management I/O space registers
FF00–FF07 8 bytes IDE bus master register
FFA0–FFA7 8 bytes Primary bus master IDE registers
FFA8–FFAF 8 bytes Secondary bus master IDE registers
Figure 50 (Page 1 of 2). DMA I/O Address Map
Address (Hex) Description Bits Byte Pointer
0000 Channel 0, Memory Address register 00–15 Yes
0001 Channel 0, Transfer Count register 00–15 Yes
0002 Channel 1, Memory Address register 00–15 Yes
0003 Channel 1, Transfer Count register 00–15 Yes
0004 Channel 2, Memory Address register 00–15 Yes
0005 Channel 2, Transfer Count register 00–15 Yes
0006 Channel 3, Memory Address register 00–15 Yes
0007 Channel 3, Transfer Count register 00–15 Yes
0008 Channels 0–3, Read Status/Write Command register 00–07
0009 Channels 0–3, Write Request register 00–02
000A Channels 0–3, Write Single Mask register bits 00–02
000B Channels 0–3, Mode register (write) 00–07
000C Channels 0–3, Clear byte pointer (write) N/A
000D Channels 0–3, Master clear (write)/temp (read) 00–07
000E Channels 0–3, Clear Mask register (write) 00–03
000F Channels 0–3, Write All Mask register bits 00–03
0081 Channel 2, Page Table Address register 3 00–07
0082 Channel 3, Page Table Address register 3 00–07
0083 Channel 1, Page Table Address register 3 00–07
0087 Channel 0, Page Table Address register 3 00–07
0089 Channel 6, Page Table Address register 3 00–07
008A Channel 7, Page Table Address register 3 00–07
008B Channel 5, Page Table Address register 3 00–07
008F Channel 4, Page Table Address/Refresh register 00–07
00C0 Channel 4, Memory Address register 00–15 Yes
00C2 Channel 4, Transfer Count register 00–15 Yes
00C4 Channel 5, Memory Address register 00–15 Yes
00C6 Channel 5, Transfer Count register 00–15 Yes
66
Technical Information Manual