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MPC8240 Integrated Processor User’s Manual
Address Translation
The lower-order address bits of the base address field of ITWR that are within the range
specified by the window size are ignored and the MPC8240 ignores the incoming
lower-order address bits (within the range specified by the window size). However, for
future compatibility, it is recommended that the base address be programmed to be
naturally aligned to the window size. For example, if the window size is programmed as 1
Mbyte, then the base address should be aligned to a 1-Mbyte boundary (as ITWR[19–12]
are not used to determine if there is a hit to the inbound translation window for a 1-Mbyte
window).
3.3.3.3 Outbound Memory Base Address Register (OMBAR)
The OMBAR, shown in Figure 3-10 and Table 3-10, defines the outbound memory
window.
Figure 3-10. Outbound Memory Base Address Register (OMBAR)—0x0_2300
Table 3-9. Bit Settings for ITWR—0x0_2310
Bits
Name
Reset
Value
R/W
Description
31
—
0
R
Reserved. Translated addresses can only be targeted at local memory in
the lower 2 Gbytes of the MPC8240 address space.
30–12 Inbound
translation
base address
Undefined
R/W
Local memory address that is the starting address for the inbound
translation window. The inbound translation window should be aligned
based on the granularity specified by the inbound window size.
11–5
—
All 0s
R
Reserved
4–0
Inbound
window size
All 0s
R/W
Inbound window size. The inbound window size is encoded as N where
the window size is 2
N+1
bytes. The minimum window size is 4 Kbytes; the
maximum window size is 1 Gbyte. Note that the inbound window size
sets the size of both the inbound memory window and the inbound
translation window.
00000 Inbound address translation disabled
00001 Reserved
...
01010 Reserved
01011 2
12
= 4 Kbyte window size
01100 2
13
= 8 Kbyte window size
01101 2
14
= 16 Kbyte window size
...
11101 2
30
= 1 Gbyte window size
11110 Reserved
11111 Reserved
Note that the inbound memory window must not overlap with the EUMB.
1
Outbound Memory Base Address
0 0 0 0 0 0 0 0 0 0 0 0
31
30
12 11
5
4
0
Reserved
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 ...