Dma i/o address map – IBM PC 300GL User Manual
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PC 300 GL and 300 PL
DMA I/O address map
Table 34. 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 (writer)/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
00–07
0082
Channel 3, Page Table Address register
00–07
0083
Channel 1, Page Table Address register
00–07
0087
Channel 0, Page Table Address register
00–07
0089
Channel 6, Page Table Address register
00–07
008A
Channel 7, Page Table Address register
00–07
008B
Channel 5, Page Table Address register
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
00C8
Channel 6, Memory Address register
00–15
Yes
00CA
Channel 6, Transfer Count register
00–15
Yes
00CC
Channel 7, Memory Address register
00–15
Yes