Intel 21555 - Manual (Page 167)

21555 Non-Transparent PCI-to-PCI Bridge User Manual 167
List of Registers
Table 87. I2O Inbound Free_List Head Pointer
Byte Offsets: 04B:048h
Bit Name R/W Description
1:0 Reserved R Reserved. Returns 0 when read.
31:2
Inbound Free Head
Ptr
R/W
Specifies the local memory Dword address of the Inbound Free_List
Head Pointer. Increments when the I2O Inbound Queue at offset 40h
is read on the primary bus. This pointer automatically wraps when it
reaches the upper boundary of the Inbound Free_List.
Table 88. I2O Inbound Post_List Tail Pointer
Byte Offsets: 04F:04Ch
Bit Name R/W Description
1:0 Reserved R Reserved. Returns 0 when read.
31:2
Inbound Post Tail
Ptr
R/W
Specifies the local memory Dword address of the Inbound Post_List
Tail Pointer. Increments when the I2O Inbound Queue at offset 40h is
written on the primary bus. This pointer automatically wraps when it
reaches the upper boundary of the Inbound Post_List.
Table 89. I2O Outbound Free_List Tail Pointer
Byte Offsets: 053:050h
Bit Name R/W Description
1:0 Reserved R Reserved. Returns 0 when read.
31:2
Outbound Free Tail
Ptr
R/W
Specifies the local memory Dword address of the Outbound
Free_List Tail Pointer. Increments when the I2O Outbound Queue
at offset 44h is written on the primary bus. This pointer
automatically wraps when it reaches the upper boundary of the
Outbound Free_List.
Table 90. I2O Outbound Post_List Head Pointer
Byte Offsets: 057:054h
Bit Name R/W Description
1:0 Reserved R Reserved. Returns 0 when read.
31:2
Outbound Post
Head Ptr
R/W
Specifies the local memory Dword address of the Outbound Post_List
Head Pointer. Increments when the I2O Outbound Queue at offset
44h is read on the primary bus. This pointer automatically wraps
when it reaches the upper boundary of the Outbound Post_List.