4. Register Descriptions
91
Tsi308 User Manual
80D4000_MA001_02
Tundra Semiconductor Corporation
www.tundra.com
4.3.3
Interrupt Definition Registers
The Interrupt Definition Registers fall under Interrupt Discovery and Configuration Capability
Block (Capability 2) located at offsets 78h-7Ch. The fields of Interrupt Definition Registers are
as shown in
, these are accessed indirectly through Index register located at offset 7Ah
and Data register located at offset 7Ch-7Fh. The Tsi308 implements 10 interrupt sources per
device, and each one of these interrupt sources implement a 64-bit definition register shown
below. The register for Interrupt 0 would occupy indexes 10h and 11h, Interrupt 1 uses 12h and
13h, etc. Bits 31:0 are accessed through the lower (even) index and bits 63:32 are accessed
through the high (odd) index.
Interrupts are programmed through Interrupt Definition Registers in RevB mode whereas they
are programmed through IOAPIC Registers in RevC mode. So, Interrupt Definition Registers
are valid only in RevB mode and they are reserved but may return non-zero value when read in
Rev.C mode. This is because these registers are used in IOAPIC mode also.
Table 22: Interrupt Definition Registers
Bit
R/W
Access
Initial
Value
Field Name and Description
63
R/C
0
Waiting for EOI:
If RQEOI is 1, then this bit is set by hardware when an interrupt request is sent and
cleared by hardware when the EOI is returned. Software may write a 1 to this bit to
clear it without an EOI.
62
R
1
PassPW:
When 1, interrupt messages will be sent with the PassPW bit set and no ordering
of the message with other upstream cycles is guaranteed. When 0, interrupt
messages will be sent with PassPW clear, and the device must guarantee that the
interrupt message will not pass upstream posted cycles within its queues. If a
device supports only one of these behaviors, this bit is read-only and indicates
which behavior is supported.
For Tsi308, this bit is hardcoded to 1.
61:56
R
0
Reserved
55:32
R/W
0
IntrInfo[55:32]
31:24
R/W
F8h
IntrInfo[31:24]:
Must default to F8h for compatibility with HT technology 1.01 and earlier devices.
Values of F9 or above must not be used or conflicts with non-interrupt address
spaces will result. Some hosts only recognize interrupts with this field set to F8h.
23:8
R/W
0
IntrInfo[23:8]
7
R
0
IntrInfo[7]
For Tsi308, this bit is hardcoded to 0.
Summary of Contents for TSI308
Page 4: ...4 Tsi308 User Manual 80D4000_MA001_02 Tundra Semiconductor Corporation www tundra com ...
Page 6: ...6 Tsi308 User Manual 80D4000_MA001_02 Tundra Semiconductor Corporation www tundra com ...
Page 20: ...20 Tsi308 User Manual 80D4000_MA001_02 Tundra Semiconductor Corporation www tundra com ...
Page 260: ...Index 260 Tsi308 User Manual 80D4000_MA001_02 Tundra Semiconductor Corporation www tundra com ...