82443BX Datasheet, PDF (11/132 Pages) Intel Corporation – Host Bridge/Controller

Architectural Overview
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The Intel^® 440BX AGPset includes the 82443BX Host Bridge and the 82371EB PIIX4E for the
I/O subsystem. The 82443BX functions and capabilities include:
• Support for single and dual Pentium II processor configurations
• 64-bit GTL+ based Host Bus Interface
• 32-bit Host address Support
• 64-bit Main Memory Interface with optimized support for SDRAM at 100 and 66/60 MHz
• 32-bit Primary PCI Bus Interface (PCI) with integrated PCI arbiter
• AGP Interface (AGP) with 133 MHz data transfer capability configurable as a Secondary PCI
Bus
• Extensive Data Buffering between all interfaces for high throughput and concurrent operations
• Mobile and “Deep Green” Desktop power management support
Figure 1-1 shows a block diagram of a typical platform based on the Intel^® 440BX AGPset. The
82443BX host bus interface supports up to two Pentium II processors at the maximum bus
frequency of 100 MHz. The physical interface design is based on the GTL+ specification optimized
for the desktop. The 82443BX provides an optimized 64-bit DRAM interface. This interface is
implemented as a 3.3V-only interface that supports only 3V DRAM technology. Two copies of the
MA, and CS# signals drive a maximum of two DIMMs each; providing unbuffered high
performance at 100 MHz. The 82443BX provides interface to PCI operating at
33 MHz. This interface implementation is compliant with PCI Rev 2.1 Specification. The
82443BX AGP interface implementation is based on Rev 1.0 of the AGP Specification. The AGP
interface supports 133 MHz data transfer rates and can be used as a Secondary PCI interface
operating at 66 MHz/3.3V supporting only a single PCI agent.
The 82443BX is designed to support the PIIX4E I/O bridge. PIIX4E is a highly integrated
multifunctional component supporting the following functions and capabilities:
• PCI Rev 2.1 compliant PCI-ISA Bridge with support for both 3.3V and 5V 33 MHz PCI
operations
• Deep Green Desktop Power Management Support
• Mobile Power Management Support
• Enhanced DMA controller and Interrupt Controller and Timer functions
• Integrated IDE controller with Ultra DMA/33 support
• USB host interface with support for 2 USB ports
• System Management Bus (SMB) with support for DIMM Serial PD
• Support for an external I/O APIC component
82443BX Host Bridge Datasheet
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