82443LX Datasheet, PDF (9/144 Pages) Intel Corporation – INTEL 440LX AGPSET: 82443LX PCI A.G.P. CONTROLLER (PAC)

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INTEL 82443LX (PAC)
1.0. OVERVIEW
PAC integrates a Host-to-PCI bridge, optimized DRAM controller and data path, and an Accelerated Graphics
Port (A.G.P.) interface. The A.G.P. is a high performance, component level interconnect, targeted at 3D
graphics applications and based on a set of performance enhancements to PCI. The I/O subsystem portion of
the PAC platform is based on the PIIX4, a highly integrated version of the Intel’s PCI-to-ISA bridge family.
The PAC is developed as the ultimate Pentium II processor platform and is targeted for emerging 3D graphics
and multimedia applications. The PAC component includes the following functions and capabilities:
• Support for single and dual Pentium II processor configurations
• 64-bit GTL+ based Host Interface
• 32-bit Host address Support
• 64/72-bit Main Memory Interface with optimized support for SDRAM
• 32-bit PCI Bus Interface with integrated PCI arbiter
• A.G.P. Interface with up to 133-MHz data transfer capability
• Extensive Data Buffering between all interfaces for high throughput and concurrent operations
Figure 1 shows a block diagram of a typical platform based on the 440LX AGPset. The PAC host bus
interface supports up to two Pentium II processors at 66 MHz. The physical interface design is based on the
GTL+ specification. The PAC provides an optimized 72-bit DRAM interface (64-bit Data plus ECC). This
interface supports 3.3V DRAM technologies. The PAC provides the interface to a PCI bus operating at 33
MHz. This interface implementation is compliant with PCI Rev 2.1 Specification. The PAC is the first Intel
product that introduces the Accelerated Graphics Port interface. The PAC A.G.P. interface implementation is
based on the A.G.P. Specification Rev 1.0. It can support up to 133-MHz data transfer rates.
PAC is designed to support the PIIX4 I/O bridge. PIIX4 is a highly integrated multi-functional component that
supports the following functions and capabilities:
• PCI Rev 2.1 compliant PCI-to-ISA Bridge with support for 33-MHz PCI operations
• Deep Green Desktop Power Management Support
• Enhanced DMA controller
• 8259 Compatible Programmable Interrupt Controller
• System Timer functions
• Integrated IDE controller with Ultra DMA/33 support
• USB host interface with support for two USB ports
• System Management Bus (SMB) with support for DIMM Serial Presence Detect
• Support for an external I/O APIC component
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