Computer Hardware User Manual

iv Intel® 460GX Chipset System Software Developer’s Manual
3 System Architecture........................................................................................................3-1
3.1 Coherency..........................................................................................................3-1
3.1.1 Processor Coherency............................................................................3-1
3.1.2 PCI Coherency......................................................................................3-2
3.1.3 AGP Coherency ....................................................................................3-2
3.2 Ordering .............................................................................................................3-2
3.3 Processor to PCI Traffic and PCI to PCI (Peer-to-Peer) Traffic .........................3-3
3.4 WXB Arbitration..................................................................................................3-3
3.5 Big-endian Support ............................................................................................3-4
3.6 Indivisible Operations.........................................................................................3-4
3.6.1 Processor Locks....................................................................................3-4
3.6.2 Inbound PCI Locks................................................................................3-5
3.6.3 Atomic Writes ........................................................................................3-5
3.6.4 Atomic Reads........................................................................................3-5
3.6.5 Locks with AGP Non-coherent Traffic ...................................................3-5
3.7 Interrupt Delivery................................................................................................3-6
3.8 WXB PCI Hot-Plug Support ...............................................................................3-6
3.8.1 Slot Power-up and Enable ....................................................................3-7
3.8.2 Slot Power-down and Disable ..............................................................3-7
4 System Address Map......................................................................................................4-1
4.1 Memory Map ......................................................................................................4-1
4.1.1 Compatibility Region .............................................................................4-1
4.1.2 Low Extended Memory Region .............................................................4-3
4.1.3 Medium Extended Memory Region.......................................................4-3
4.1.4 High Extended Memory (above 4G)......................................................4-4
4.1.5 Re-mapped Memory Areas ...................................................................4-4
4.2 I/O Address Map ................................................................................................4-5
4.3 Devices View of the System Memory Map.........................................................4-7
4.4 Legal and Illegal Address Disposition ................................................................4-8
5 Memory Subsystem ........................................................................................................5-1
5.1 Organization.......................................................................................................5-1
5.1.1 DIMM Types..........................................................................................5-3
5.2 Interleaving/Configurations ................................................................................5-4
5.2.1 Summary of Configuration Rules ..........................................................5-5
5.2.2 Non-uniform Memory Configurations ....................................................5-5
5.3 Bandwidth ..........................................................................................................5-5
5.4 Memory Subsystem Clocking.............................................................................5-6
5.5 Supporting Features...........................................................................................5-6
5.5.1 Auto Detection.......................................................................................5-6
5.5.2 Removing a Bad Row ...........................................................................5-6
5.5.3 Hardware Initialization...........................................................................5-7
5.5.4 Memory Scrubbing ................................................................................5-7
6 Data Integrity and Error Handling...................................................................................6-1
6.1 Integrity ..............................................................................................................6-1
6.1.1 System Bus ...........................................................................................6-1
6.1.2 DRAM....................................................................................................6-2
6.1.3 Expander Buses....................................................................................6-2
6.1.4 PCI Buses .............................................................................................6-2
6.1.5 AGP.......................................................................................................6-2