SECTION 4
PCI 9080
REGISTERS
PLX Technology, Inc., 1997
Page 70
Version 1.02
4.4.12 (DMCFGA; PCI:2Ch, LOC:ACh) PCI Configuration Address Register for Direct Master to
PCI IO/CFG
Table 4-44. (DMCFGA; PCI:2Ch, LOC:ACh) PCI Configuration Address Register for Direct Master to PCI IO/CFG
Field
Description
Read
Write
Value after Reset
1:0
Configuration Type (00=Type 0, 01=Type 1).
Yes
Yes
0
7:2
Register Number. If different register read/write is needed, this register value must
be programmed and a new PCI configuration cycle must be generated.
Yes
Yes
0
10:8
Function Number.
Yes
Yes
0
15:11
Device Number.
Yes
Yes
0
23:16
Bus Number.
Yes
Yes
0
30:24
Reserved.
Yes
No
0
31
Configuration Enable. Value of 1 allows local to PCI I/O accesses to be converted
to a PCI configuration cycle. The parameters in this table are used to generate the
PCI configuration address.
Yes
Yes
0
Note:
1 Cycles).”
Refer to the Configuration Cycle Generation example in Section 3.6.1.6, “CFG (PCI Configuration Type 0 or Type
4.4.13 (LAS1RR; PCI:F0h, LOC:170h) Local Address Space 1 Range Register for PCI to Local
Bus
Table 4-45. (LAS1RR; PCI:F0h, LOC:170h) Local Address Space 1 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 1 maps into
PCI memory space. Value of 1 indicates address space 1 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 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 1. Each of the bits corresponds to a PCI address bit. Bit 31 corresponds to
Address bit 31. Write a value of 1 to all bits that must be included in decode and a 0
to all others (Used in conjunction with PCI Configuration Register Ch 1). Default is
1 MB.
Yes
Yes
FFF0000h
Note:
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 2.1 spec.
If QSR bit 0 is set, defines PCI Base Address 0.