How HyperTransport Handles Configuration Accesses

While HyperTransport configuration cycles are compatible with PCI, there are some important differences.

Configuration Cycles Are Memory Mapped

To generate a configuration space read or write, a HyperTransport bridge simply sends a RdSized or non-posted WrSized request using a reserved address range in the 40-bit HyperTransport memory map. This 32MB range, recognized by all devices, is shown in Figure 13-2 on page 312.

Figure 13-2. Configuration Space In The HyperTransport Address Map

How The 32MB Configuration Area Is Used

The 32MB HyperTransport memory map address space reserved for configuration ...

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