2. PCI Interface
80
PowerSpan II User Manual
80A1010_MA001_09
Integrated Device Technology
www.idt.com
2.6.12
I
2
0 Outbound Queue
A read from the I
2
O Outbound Queue returns the next MFA from the I
2
O Outbound Post List FIFO.
This is a destructive read.
A write to this offset places a Free Host MFA into the I
2
O Outbound Free List FIFO. PowerSpan II
accepts the write cycle as a posted write and is responsible for completing the cycle on the destination
bus.
When the I
2
0 Interface in PowerSpan II is not enabled, the OUT_Q register is not visible to read or
write access. The register essentially disappears from all PowerSpan II memory maps.
Register Name: OUT_Q
Register Offset: 044
PCI
Bits
Function
PPC
Bits
31-24
MFA
0-7
23-16
MFA
8-15
15-08
MFA
16-23
07-00
MFA
24-31
Name
Type
Reset
By
Reset
State
Function
MFA[31:0]
R/W
Px_RST
0
Outbound Message Frame Address
The Outbound Message Frame Address specify locations in
the Host memory map where Outbound Message Frames
reside.
The Message Frame Address is the Host memory address of
the Message Frame.