IBM 6268, Technical Information Manual

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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 34 (Page 3 of 3). I/O address map
Address (Hex) Size Description
0480–048F 16 bytes DMA channel high page registers
0490–0CF7 1912 bytes Available
0CF8–0CFB 4 bytes PCI Configuration address register
0CFC–0CFF 4 bytes PCI Configuration data register
LPT n
+
400h 8 bytes ECP port, LPT n base address
+
hex 400
0CF9 1 byte Turbo and reset control register
0D00–FFFF 62207 bytes Available
Figure 35 (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 2 00–07
0082 Channel 3, Page Table Address register 2 00–07
0083 Channel 1, Page Table Address register 2 00–07
0087 Channel 0, Page Table Address register 2 00–07
0089 Channel 6, Page Table Address register 2 00–07
008A Channel 7, Page Table Address register 2 00–07
008B Channel 5, Page Table Address register 2 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
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