3-12
MPC8240 Integrated Processor User’s Manual
Address Translation
.
Figure 3-6. Inbound PCI Address Translation
Inbound address translation only allows address translation to the local memory space (the
lower 1 Gbyte of the address space). This means that an external PCI master cannot access
devices in the ROM/Port X address space when using inbound address translation. Since
the local memory space is restricted to addresses below 0x4000_0000 (1 Gbyte), any access
that gets translated above 0x4000_0000 triggers a memory select error. Thus, the entire
inbound translation window must be programmed to be below 0x4000_0000.
The local memory base address register (LMBAR) and the inbound translation window
register (ITWR) specify the location and size of the inbound memory window and the
inbound translation window. These registers are described in Section 3.3.3, “Address
Translation Registers.” Inbound address translation may be disabled by programming the
inbound window size in the ITWR to all zeros. If inbound translation is disabled, the
MPC8240 ignores all PCI memory transactions.
Note that overlapping the inbound memory window and the outbound translation window
is not supported and can cause unpredictable behavior. Also note that the inbound memory
window must not overlap the EUMB as specified by the PCSRBAR (PCI memory space
view). See Section 3.4, “Embedded Utilities Memory Block (EUMB),” for more
information.
Processor
PCI memory space
Local memory space
0
4G
0
4G
PCI Memory Space
Inbound memory
Local memory
Inbound translation
window
Inbound address
translation
base address
Inbound window
Inbound translation
2G
base address
window
size
1G
View
Core
Summary of Contents for MPC8240
Page 1: ...MPC8240UM D Rev 1 1 2001 MPC8240 Integrated Processor User s Manual ...
Page 38: ...xviii MPC8240 Integrated Processor User s Manual TABLES Table Number Title Page Number ...
Page 48: ...xlviii MPC8240 Integrated Processor User s Manual Acronyms and Abbreviations ...
Page 312: ...6 94 MPC8240 Integrated Processor User s Manual ROM Flash Interface Operation ...
Page 348: ...7 36 MPC8240 Integrated Processor User s Manual PCI Host and Agent Modes ...
Page 372: ...8 24 MPC8240 Integrated Processor User s Manual DMA Register Descriptions ...
Page 394: ...9 22 MPC8240 Integrated Processor User s Manual I2O Interface ...
Page 412: ...10 18 MPC8240 Integrated Processor User s Manual Programming Guidelines ...
Page 454: ...12 14 MPC8240 Integrated Processor User s Manual Internal Arbitration ...
Page 466: ...13 12 MPC8240 Integrated Processor User s Manual Exception Latencies ...
Page 516: ...16 14 Watchpoint Trigger Applications ...
Page 538: ...B 16 MPC8240 Integrated Processor User s Manual Setting the Endian Mode of Operation ...
Page 546: ...C 8 MPC8240 Integrated Processor User s Manual ...
Page 640: ...INDEX Index 16 MPC8240 Integrated Processor User s Manual ...