2. PCI Interface
76
PowerSpan II User Manual
80A1010_MA001_09
Integrated Device Technology
www.idt.com
2.6.8
I
2
O Standard Registers
This section defines the standard I
2
O register set supported by PowerSpan II. These registers are
accessible within the PowerSpan II I
2
O target image. In
all standards-based registers are in
italics.
The I
2
O Shell Interface is located in the first 4 Kbytes of the PowerSpan II I
2
O target image. The I
2
O
Inbound Message Frames occupies offsets above the 4 Kbyte point of the PowerSpan II I
2
O target
image. The upper limit of the I
2
O Inbound Message Frames is determined by the size of the PowerSpan
II I
2
O target image, as defined by the PCI_I2O_CTL[BS] register.
The offset of the I
2
O Host Outbound Index Register is programmed in the I
2
O Host Outbound Index
Offset Register (HOST_OIO) of the PowerSpan II Register Map.
The following tables show the I
2
O register definitions.
Table 10: PowerSpan II I20 Target Image Map
Offset
(HEX)
Register
Mnemonic
Register Name
0x000-028
PowerSpan II Reserved
0x030
OPL_IS
I
2
0 Outbound Post List Interrupt Status Register
0x034
OPL_IM
I
2
0 Outbound Post List Interrupt Mask Register
0x038
PowerSpan II Reserved
0x040
IN_Q
I
2
0 Inbound Queue
0x044
OUT_Q
I
2
0 Outbound Queue
0x048-[HOST_OIO]-4
PowerSpan II Reserved
[HOST_OIO]
HOST_OI
I
2
O Host Outbound Index Register
[HO4-0xFF
PowerSpan II Reserved
0x100-xxx
I
2
0 Inbound Message Frames