Intel® 82854 Graphics Memory Controller Hub (GMCH)

2.6Hub Interface

A proprietary interconnect connects the GMCH to the ICH4-M. All communication between the GMCH and the ICH4-M occurs over the Hub interface 1.5. The Hub interface runs at 66 MHz (266-MB/s).

2.7Address Decode Policies

Host initiated I/O cycles are positively decoded to the GMCH configuration space and subtractively decoded to the Hub interface. Host initiated system memory cycles are positively decoded to DDR SDRAM and are again subtractively decoded to the Hub interface, if less than 4 GB. System memory accesses from the Hub interface to DDR SDRAM will be snooped on the FSB.

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D15343-003

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Intel D15343-003 manual Hub Interface, Address Decode Policies