SC2200 NSC [National Semiconductor], SC2200 Datasheet - Page 266

• Manufacturer Part Number: SC2200
• Description: Thin Client On a Chip
• Manufacturer: NSC [National Semiconductor]

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Core Logic Module
5.4.3.1
F2 Index 20h, Base Address Register 4 (F2BAR4), points
to the base address of where the registers for IDE control-
Offset 00h
Offset 01h
Offset 02h
Offset 03h
Offset 04h-07h
31:2
7:4
2:1
4:3
1:0
Bit
3
0
7
6
5
2
1
0
IDE Controller Support Registers
Description
Reserved. Must be set to 0. Must return 0 on reads.
Read or Write Control. Sets the direction of bus master transfers.
0: PCI reads performed.
1: PCI writes performed.
This bit should not be changed when the bus master is active.
Reserved. Must be set to 0. Must return 0 on reads.
Bus Master Control. Controls the state of the bus master.
0: Disable master.
1: Enable master.
Bus master operations can be halted by setting this bit to 0. Once an operation has been halted, it cannot be resumed. If this
bit is set to 0 while a bus master operation is active, the command is aborted and the data transferred from the drive is dis-
carded. This bit should be reset after completion of data transfer.
Simplex Mode. (Read Only) Indicates if both the primary and secondary channel operate independently.
0: Yes.
1: No (simplex mode).
Drive 1 DMA Enable. When asserted, allows Drive 1 to perform DMA transfers.
0: Disable.
1: Enable.
Drive 0 DMA Enable. When asserted, allows Drive 0 to perform DMA transfers.
0: Disable.
1: Enable.
Reserved. Must be set to 0. Must return 0 on reads.
Bus Master Interrupt. Indicates if the bus master detected an interrupt.
0: No.
1: Yes. Write 1 to clear.
Bus Master Error. Indicates if the bus master detected an error during data transfer.
0: No.
1: Yes. Write 1 to clear.
Bus Master Active. Indicates if the bus master is active.
0: No.
1: Yes.
Pointer to the Physical Region Descriptor Table. This bit field contains a PRD table pointer for IDE Bus Master 0.
When written, this field points to the first entry in a PRD table. Once IDE Bus Master 0 is enabled (Command Register bit 0
= 1), it loads the pointer and updates this field (by adding 08h) so that is points to the next PRD.
When read, this register points to the next PRD.
Reserved. Must be set to 0.
Table 5-36. F2BAR4+I/O Offset: IDE Controller Configuration Registers
(Continued)
IDE Bus Master 0 Command Register — Primary (R/W)
IDE Bus Master 0 PRD Table Address — Primary (R/W)
IDE Bus Master 0 Status Register — Primary (R/W)
Not Used
Not Used
266
ler configuration are located. Table 5-36 gives the bit for-
mats of the I/O mapped IDE Controller Configuration
registers that are accessed through F2BAR4.
Reset Value: 00000000h
Reset Value: 00h
Reset Value: 00h
Revision 3.0