MVME5100 Single Board Computer Programmer's Reference Guide

The fields within XSADD3 are defined as follows:
Registers
START Start Address. This field determines the start address of
a particular memory area on the PPC bus which will be
used to access PCI bus resources. The value of this field
will be compared with the upper 16 bits of the incoming
PPC address.
END End Address. This field determines the end address of a
particular memory area on the PPC bus which will be used
to access PCI bus resources. The value of this field will be
compared with the upper 16 bits of the incoming PPC
address.
PPC Slave Offset/Attribute (3) Registers
Address XSOFF3/XSATT3 - $FEFF005C
Bit 0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
Name XSOFF3 XSATT3
Operation R/W R
Reset Regbase 0xfeff0000 => $8000
Regbase 0xfefe0000 => $7000
REN
WEN
The PPC Slave Offset Register 3 (XSOFF3) contains offset information
associated with the mapping of PPC memory space to PCI I/O space. The
field within the XSOFF3 register is defined as follows:
XSOFFx PPC Slave Offset. This register contains a 16-bit offset
that is added to the upper 16 bits of the PPC address to
determine the PCI address used for transfers from the PPC
bus to PCI. This offset allows PCI resources to reside at
addresses that would not normally be visible from the
PPC bus. It is initialized to $8000 to facilitate a zero based
access to PCI space.
http://www.motorola.com/computer/literature 2-91
$00
WPEN
IOM
R/W
R/W
R
R/W
R
R
R
R/W
1
1
0
0
0
0
0
0
2