12. Register Descriptions
362
PowerSpan II User Manual
80A1010_MA001_09
Integrated Device Technology
www.idt.com
12.5.66
I2O Inbound Free List Bottom Pointer Register
BOT:
This pointer gives the address offset for the Inbound Free List Bottom Pointer from PB_I2O_BS.
This pointer is initialized by the IOP and maintained by PowerSpan II. This pointer is incremented by
four for each PCI read from the Inbound Queue.
Register Name: IFL_BOT
Register Offset: 0x510
PCI
Bits
Function
PB
Bits
31-24
PB_I2O_BS
0-7
23-16
PB_I2O_BS
BOT
8-15
15-08
BOT
16-23
07-00
BOT
0
0
24-31
I
Name
Type
Reset
By
Reset
State
Function
PB_I2O_BS
[11:0]
R
PRI_RST
0
Processor Bus I2O Base Address
BOT [17:0]
R/W
PRI_RST
0
Inbound Free List Bottom Pointer
This pointer gives the address offset for the Inbound
Free List Bottom Pointer from PB_I2O_BS.
If the initial values of the Inbound Free List Bottom and Top pointers are the
same, the inbound free list is empty. The user can program the Top pointer to be
four less than the Bottom pointer and then write to the INCR bit in the
Free List Top Pointer Increment Register” on page 364
to make the inbound free
list full.