SECTION 4
PCI 9080
REGISTERS
PLX Technology, Inc., 1997
Page 63
Version 1.02
4.4 LOCAL CONFIGURATION REGISTERS
4.4.1 (LAS0RR; PCI:00h, LOC:80h) Local Address Space 0 Range Register for PCI to Local
Bus
Table 4-33. (LAS0RR; PCI:00h, LOC:80h) Local Address Space 0 Range Register for PCI to Local Bus
Field
Description
Read
Write
Value after Reset
0
Memory Space Indicator. Value of 0 indicates Local address space 0 maps into PCI
memory space. Value of 1 indicates address space 0 maps into PCI I/O space.
Yes
Yes
0
2:1
If mapped into memory space, encoding is as follows:
2/1 Meaning
0 0
Locate anywhere in 32 bit PCI address space
0 1
Locate below 1 MB in PCI address space
1 0
Locate anywhere in 64 bit PCI address space
1 1
Reserved
If mapped into I/O space, bit 1 must be set to 0.
Bit 2 is included with bits [31:3] to indicate decoding range.
Yes
Yes
0
3
If mapped into memory space, a value of 1 indicates reads are prefetchable (bit has
no effect on the operation of the PCI 9080, but is used for system status). If
mapped into I/O space, bit is included with bits [31:2] to indicate decoding range.
Yes
Yes
0
31:4
Specifies which PCI address bits to use for decoding a PCI access to local bus
space 0. Each bit corresponds to a PCI address bit. Bit 31 corresponds to Address
bit 31. Write a value of 1 to all bits to be included in decode and a 0 to all others
(used in conjunction with PCI Configuration register 18h). Default is 1 MB.
Yes
Yes
FFF0000h
Notes:
Range (
not
Range register) must be power of 2. “Range register value” is the inverse of range.
User should limit all I/O spaces to 256 bytes per PCI v2.1 spec.
4.4.2 (LAS0BA; PCI:04h, LOC:84h) Local Address Space 0 Local Base Address (Remap)
Register
Table 4-34. (LAS0BA; PCI:04h, LOC:84h) Local Address Space 0 Local Base Address (Remap) Register
Field
Description
Read
Write
Value after Reset
0
Space 0 Enable. Value of 1 enables decoding of PCI addresses for Direct Slave
access to local space 0. Value of 0 disables decoding. If this bit is set to 0, the PCI
BIOS may not allocate (assign) the base address for Space 0.
Note:
Must be set to 1 for any Direct Slave access to Space 0
Yes
Yes
0
1
Reserved.
Yes
No
0
3:2
If local space 0 is mapped into memory space, bits are not used. If mapped into I/O
space, bit is included with bits [31:4] for remapping.
Yes
Yes
0
31:4
Remap of PCI Address to Local Address Space 0 into a Local Address Space. The
bits in this register remap (replace) the PCI Address bits used in decode as the
Local Address bits.
Note:
Remap Address value must be multiple of Range (
not
the Range
register).
Yes
Yes
0