Introduction
The Intel® 945G/945GZ/945GC/945P/945PL Express chipsets are designed for use with the Intel® CoreTM2 Duo, Intel® Celeron 400 series, Intel® Pentium® D processor, Intel® Pentium® 4 processor. Additionally, Intel® 945GC Express chipsets also support Intel® AtomTM Processor 200 Series and Intel® AtomTM Processor 300 Series. Each chipset contains two components: GMCH (or MCH) for the host bridge and I/O Controller Hub 7 (ICH7) for the I/O subsystem. The 82945G GMCH is part of the 945G Express chipset, 82945GZ GMCH is part of the 945GZ Express chipset, 82945GC GMCH is part of the 945GC Express chipset, 82945P MCH is part of the 945P Express chipset, and 82945PL MCH is part of the 945PL Express chipset. The ICH7 is the seventh generation I/O Controller Hub and provides a multitude of I/O related functions. Figure 1-1, Figure 1-2, and Figure 1-3 show example system block diagrams for the 945G, 945GZ, 945GC and 945P/945PL Express chipsets.

This document is the datasheet for the Intel® 82945G Graphics and Memory Controller Hub (GMCH), Intel® 82945GZ Graphics and Memory Controller Hub (GMCH), Intel® 82945GC Graphics and Memory Controller Hub (GMCH), Intel® 82945P Memory Controller Hub (MCH), and Intel® 82945PL Memory Controller Hub (MCH). Topics covered include; signal description, system memory map, PCI register description, a description of the (G)MCH interfaces and major functional units, electrical characteristics, ballout definitions, and package characteristics.