Field Name Bits Default Description
Interrupt Pin 7:0 01h Hard-wired to 01h.
Interrupt Pin Register: This register identifies the interrupt pin a device uses. Since the IDE host controller uses
IRQ14, this value is supposed to be 00. However, the IDE controller will generate the PCI interrupt INTA# signal on
the PCI bus. Therefore, this pin register is set to 01h.
Min_gnt - R - 8 bits - [PCI_Reg:3Eh] Field Name Bits Default Description
Minimum Grant 7:0 00h Hard-wired to 0’s and always read as 0’s.
Min_gnt Register: This register specifies the desired settings for how long of a burst the IDE host controller needs
assuming a clock rate of 33MHz. The value specifies a period of time in units of ¼ microseconds.
Max_latency - R - 8 bits - [PCI_Reg:3Fh] Field Name Bits Default Description
Maximum Latency 7:0 00h Hard-wired to 0’s and always read as 0’s.
Max_latency Register: This register specifies the Maximum Latency time required before the IDE host controller as
a bus-master can start an accesses.
IDE PIO Timing - RW - 32 bits - [PCI_Reg:40h] Field Name Bits Default Description
Primary Slave Data
Register Command
Recovery Width
3:0 9h Slave Data register command recovery width for Primary IDE
bus slave PIO device.
Primary Slave Data
Register Command width
7:4 9h Slave Data register command width for Primary IDE bus slave
PIO device.
Primary Master Data
Register Command
Recovery Width
11:8 9h Master Data register command recovery width for primary IDE
bus Master PIO device.
Primary Master Data
Register Command
Width
15:12 9h Master Data register command width for Primary IDE bus
Master PIO device.
Reserved 31:16 0000h Reserved. Always read as 0’s
IDE PIO Timing Register: This register controls the IDE interface and selects the timing of the IDE PIO bus-master
cycles.
Note: Relation of setting value and actual timing of each mode are
PIO Mode 4 3 2 1 0
Command Width 2(90ns) 2(90ns) 3(120ns) 4(150ns) 9(270ns)
Recover Width 0(30ns) 2(90ns) 4(150ns) 7(240ns) 9(270ns)
The above timings are valid and A-Link clock is always 66MHz.
Actual timing is setting value + 1 A-Link clock cycle.
IDE Legacy DMA (Multi-words DMA) Timing Modes - RW - 32 bits - [PCI_Reg:44h] Field Name Bits Default Description
Primary Slave DMA
Command Recovery
Width
3:0 Fh Slave DMA command recovery width for Primary IDE bus
Slave DMA device.
Primary Slave DMA
Command Width
7:4 Fh Slave DMA command width for Primary IDE bus Slave DMA
device.
Primary Master DMA
Command Recovery
Width
11:8 Fh Master DMA Command recovery width for primary IDE bus
Master DMA device.
Primary Master DMA
Command Width
15:12 Fh Master DMA Command width for Primary IDE bus Master
DMA device.
Reserved 31:16 0h Reserved. Always read as 0’s