12. Register Descriptions
375
PowerSpan II User Manual
80A1010_MA001_09
Integrated Device Technology
www.idt.com
12.5.79
I2O Host Outbound Index Alias Register
This register is required for PowerSpan II I
O Outbound Option support. This is an alias to the I2O
Host Outbound Index Register in the PowerSpan II I2O Target Image. The Host maintains this register.
This register indicates the address in Host memory from which the Host is to retrieve the next
Outbound XMFA. This register is initialized by the IOP with an index received from the Host in an I2O
message. The register will be written by the Host during I2O Outbound Option message passing.
If the I2O Host Outbound Index Register and the I2O IOP Outbound Index Register differ, then the
Outbound Post List Interrupt Status bit is set in the OPL_IS register at offset 0x30 of the PCI I2O target
Image. When these registers contain the same Host memory address, the interrupt is cleared.
This feature is only supported when the I2O Outbound Option is enabled with XI2O_EN bit in the
“I2O Control and Status Register” on page 357
The HOPL_SIZE field in the
“I2O Control and Status Register” on page 357
of this Index Register.
Register Name: HOST_OIA
Register Offset: 0x544
PCI
Bits
Function
PB
Bits
31-24
OIA
0-7
23-16
OIA
8-15
15-08
OIA
16-23
07-00
OIA
0
0
24-31
Name
Type
Reset
By
Reset
State
Function
OIA[29:0]
R/W
PRI_RST
0
Host Outbound Index Alias Register