17.3.3
PCI
Target Map Configuration
Two PCI bridge address ranges
in
PCI memory space are mapped to PLB space: PCI target map
(PTM1) and PTM2
(PTMO
is reserved).
Each PTM is configured using the
following registers (n is 1
or
2,
corresponding with PTM1 and
PTM2,
respectively).
•
PTMnMemory Size (PCILO_PTMnMS)
• PTMnLocal
Address (PCILO_PTMnLA)
•
PTMnBAR (PCILO_PTMnBAR)
The size of each PTM is programmable, using the PCILO_PTMnMS registers. The size is a power of
2,
and ranges from
4KB-4GB.
The PLB and PCI address spaces for each PTM are aligned to this
size
..
The address range of PLB space accessed through each PTM is also programmable, enabling
address translation between the PCI bus and the PLB. The PLB address range is defined
in
the
PCILO_PTMnLA registers.
The
location of each PTM
in
PCI memory space is programmable, using the PCIPCILO_PTMnBAR
registers.
The PTMs are
enabled and disabled using PCICO_CMD[MA]. PTM address ranges and sizes should
be initialized before being enabled. If the PCI bridge is not the host bridge, the local processor must
initialize the PTM size before enabling host configuration setting the Host Configuration Enable (HCE)
field of the Bridge Options 2 register (PCICO_BRDGOPT2). This ensures that the host experiences
proper behavior from the
PCILO_PTMnBAR registers. Note that PTM1 is always enabled. The PTM1
registers must
always be initialized.
Figure 17-6 shows the detail of the PMM/BAR register sets used to map PCI memory regions to PLB
address space.
PTM#/BAR#
PTM # Local Address
~
S
~
PTM # Mask/Attribute
t-
\
--------
I
PCI Memory
PLB Memory
ize
Region
1
Region
1
PTM # BAR - PCI
V
Base Address
1
Size
J
Starting Address
Starting Address
Figure 17-6.
PTM
Register Sets Map
PCI
Address Space
to
PLB Address Space
Preliminary
PCI Interface
17-9
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