12. Register Descriptions
258
PowerSpan II User Manual
80A1010_MA001_09
Integrated Device Technology
www.idt.com
12.5.6
PCI-1 Register Image Base Address Register
This register specifies the 4-KByte aligned base address of the device’s register space in PCI Memory
Space. The Register space is only 4 KByte, therefore the PCI address lines [11:0] are used to select the
register.
A write must occur to this register before the device’s registers can be accessed through PCI memory
transactions. This write can be performed with a PCI Configuration transaction or a register access by
the local processor.
A Base Address of 0x00000 is not a supported base address and the register image does not respond to
PCI transactions as a target device when 0x00000 is written to this field
—
the image is disabled.
PowerSpan II supports a Base Address of 0x00000 if the BAR_EQ_0 bit is set in the
Control and Status Register” on page 318
.
Writes are enabled to this register only when the BSREG_BAR_EN bit in the
Control and Status Register” on page 283
is set.
Register Name: P1_BSREG
Register Offset: 0x014
PCI
Bits
Function
PB
Bits
31-24
BA
0-7
23-16
BA
8-15
15-08
BA
0
0
0
0
16-23
07-00
0
0
0
0
PRFTCH
TYPE
SPACE
24-31
Name
Type
Reset
By
Reset
State
Function
BA[19:0]
R/W
P1_RST
0
Base Address
PRFTCH
R
P1_RST
0
Prefetchable
Memory is not prefetchable
TYPE [1:0]
R
P1_RST
0
Type
00 = locate anywhere in 32-bit address space
SPACE
R
P1_RST
0
PCI Bus Address Space
0 = Memory