12. Register Descriptions
372
PowerSpan II User Manual
80A1010_MA001_09
Integrated Device Technology
www.idt.com
12.5.76
I2O Outbound Post List Top Pointer Register
TOP:
This pointer gives the address offset for the Outbound Post List Top Pointer from PB_I2O_BS.
This pointer is initialized by the IOP and can be incremented by four by writing 1 to the INCR bit in the
OPL_TOP_INC register.
Register Name: OPL_TOP
Register Offset: 0x538
PCI
Bits
Function
PB
Bits
31-24
PB_I2O_BS
0-7
23-16
PB_I2O_BS
TOP
8-15
15-08
TOP
16-23
07-00
TOP
0
0
24-31
Name
Type
Reset
By
Reset
State
Function
PB_I2O_BS
[11:0]
R
PRI_RST
0
Processor Bus I2O Base Address
TOP [17:0]
R/W
PRI_RST
0
Outbound Post List Top Pointer
This pointer gives the address offset for the Outbound
Post List Top Pointer from PB_I2O_BS.
The initial values of the Outbound Post List Bottom and Top pointers must be
the same. After these pointers are initialized, the outbound post list is empty.