Registers
http://www.motorola.com/computer/literature 2-91
2
The fields within XSADD3 are defined as follows:
START Start Address. This field determines the start addre ss 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
The PPC Slave Offset Register 3 (XSOFF3) contains offset information
associated with the mapping of PPC m emory space to PCI I/O space. The
field within the XSOFF3 register is defined as follows:
XSOFFxPPC 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 re side at
addresses that would not normally be visible from the
PPC bus. It is initialized to $8000 to facilit ate a zero based
access to PCI space.
Address XSOFF3/XSATT3 - $FEFF005C
Bit
0
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Name XSOFF3 XSATT3
REN
WEN
WPEN
IOM
Operation R/W R
R/W
R/W
R
R/W
R
R
R
R/W
Reset Regbase 0xfeff0000 => $8000
Regbase 0xfefe0000 => $7000 $00
1
1
0
0
0
0
0
0