Serial and Parallel ATA Drive Guidelines and Features
4.6.1 Legacy Mode
The Legacy mode is used to access devices attached to the embedded IDE controllers. Each
channel requires two fixed I/O address ranges and an IRQ for each.
■
Primary Channel
❏
Command block: 1F0h - 1F7h
❏
Control block: 3F6h
❏
IRQ: 14
■
Secondary Channel
❏
Command block: 170h - 177h
❏
Control block: 376h
❏
IRQ: 15
4.6.2 Native Mode
The native mode is used to access devices attached to add-in cards and is not supported by many
legacy operating systems. Addresses are assigned by PCI Plug-n-Play BIOS and the IRQ is
shared with multiple controllers. Base Address Registers for the Command and Control Block
are found in the PCI Configuration Space.
■
Offset 10h—Primary Command base address
■
Offset 14h—Primary Control base address
■
Offset 18h—Secondary Command base address
■
Offset 1Ch—Secondary Control base address
4–10
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Service Reference Guide, d500