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Chapter 5 Input/Output Interfaces
Compaq Deskpro 4000N and 4000S Personal Computers
First Edition – September 1997
5-2
5.2.1.1 IDE Configuration Registers
The IDE interface is handled by the 82586 component and configured as a PCI device with bus
mastering capability. The PCI configuration registers for the IDE controller function (PCI device
#20, function #1) are listed in Table 5-1.
Table 5–1
. IDE PCI Configuration Registers
Table 5-1.
EIDE PCI Configuration Registers (82586, Function 1)
PCI
Conf.
Addr. Register
Value
on
Reset
PCI
Conf.
Addr. Register
Value
on
Reset
00-01h Vender ID 1106h 40h Chip Enable reg.
02-03h Device ID 0586h 41h IDE Configuration 00h
04-05h PCI Command 0000h 42h Miscellaneous Control
06-07h PCI Status 0000h 43h FIFO Configuration
08h Revision ID 0Ah 44h Miscellaneous Control
09h Programming xxxxh 45h Miscellaneous Control
0Ah Sub-Class 01h 46h Miscellaneous Control C0h
0Bh Base Class Code 01h 48h Sec. IDE Drv.1 Timing Cntrl. A8h
0Dh Master Latency Timer 0000h 49h Sec. IDE Drv.0 Timing Cntrl A8h
0Eh Header Type 80h 4Ah Pri. IDE Drv.1 Timing Cntrl. A8h
10-13h Pri. Data/Cmd Base Addr. 1F0h 4Bh Pri. IDE Drv.0 Timing Cntrl A8h
14-17h Pri. Cntrl./Sts. Base Addr. 3F4h 4Ch Address Setup Time
18-1Bh Sec. Data/Cmd Base Addr. 170h 4E, 4Fh Non-1F0h Port Drive Timing 00FFh
1C-1Fh Sec. Cntrl./Sts. Base Addr. 374h 50h Sec. Drive 1 Ext. Timing 00h
20-23h Bus Mstr. Cntrl. Reg. Base Addr. 51h Sec. Drive 0 Ext. Timing 00h
24-27h Mem. Base Addr. for MM I/O 52h Pri. Drive 1 Ext. Timing 00h
3Ch Interrupt Line 0Eh 53h Pri. Drive 0 Ext. Timing 00h
3Dh Interrupt Pin 54-5Fh Reserved
3Eh Min_GNT 60, 61h, Sector Size for Pri. IDE 200h
3Fh Min_LAT 68, 69h Sector Size for Sec. IDE 200h
NOTE:
Assume unmarked gaps are reserved and/or not used.
5.2.1.2 IDE Bus Master Control Registers
The IDE interface can perform PCI bus master operations using the I/O mapped control registers
listed in Table 5-2.
Table 5–2.
IDE Bus Master Control Registers
Table 5-2.
IDE Bus Master Control Registers
I/O Addr.
Offset
Size
(Bytes) Register
Default
Value
00h 2 Bus Master IDE Command (Primary) 00h
02h 2 Bus Master IDE Status (Primary) 00h
04h 4 Bus Master IDE Descriptor Ptr (Pri.) 0000 0000h
08h 2 Bus Master IDE Command (Secondary) 00h
0Ah 2 Bus Master IDE Status (Secondary) 00h
0Ch 4 Bus Master IDE Descriptor Ptr (Sec.) 0000 0000h