MultiProcessor Specification
4.4.1System Address Space Mapping Entries
System Address Space Mapping entries define the system addresses that are visible on a particular bus. Each bus defined in the Base Table can have any number of System Address Space Mapping entries included in the Extended Table. Thus, individual buses can be configured to support different address ranges, thereby decreasing the amount of bus traffic on a given bus and increasing the overall system performance. Each consecutive address range that is usable by the operating system to access devices on a given bus has a System Address Space Mapping entry. Figure
3 1 | 2 8 2 7 | 24 2 3 | 2 0 1 9 | 1 6 | 1 5 | 1 2 1 1 | 8 | 7 | 4 | 3 | 0 |
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| ADDRESS LENG TH |
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| 10H | |||
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| 0CH |
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| ADDRES S BASE |
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| 08H | |||
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| 04H |
ADDRESS TYPE | BUS ID |
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| ENTRY TYPE | 00H | ||||
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| 128 |
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3 1 | 2 8 2 7 | 24 2 3 | 2 0 1 9 | 1 6 | 1 5 | 1 2 1 1 | 8 | 7 | 4 | 3 | 0 |
Figure 4-9. System Address Space Entry
Version 1.4 |