Motherboard Layout and Routing Guidelines

The methodology that Intel recommends is known as “Sensitivity Analysis”. In sensitivity analysis, interconnect parameters are varied to understand how they affect system timing and signal integrity. Sensitivity analysis can be further broken into two types of analysis, parametric sweeps and Monte Carlo analysis, which are described below.

Figure 2-13. Pre-layout simulation process

Interconnect Simulations (Transmission-Line)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Sensitivity Analyses

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Performance as function of Length

 

 

 

 

 

Monte Carlo

 

 

(flight time, signal quality, etc.)

 

 

 

(pass/fail as function of length)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

D U A L K L A M A T H P R O C E S S O R C A R D S O L U T IO N S P A C E

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

M o n t e C a rl o

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Solution Space

S o l u t io n s p a c e

2.4Placement & Layout

Once the pre-layout simulation is completed, route the board using the solution space resulting from the sensitivity analysis.

2.5Post-Layout Simulation

Following layout, extract the traces and run simulations to verify that the layout meets timing and noise requirements. A small amount of trace “tuning” may be required, but experience at Intel has shown that sensitivity analysis dramatically reduces the amount of tuning required.

The post layout simulations should take into account the expected variation for all interconnect parameters. For timing simulations, use a VREF of 2/3 VTT ± 2% for both the Intel® Pentium® II processor and Intel® 440GX AGPset components. Flight times measured from the Pentium II processor edge fingers to other system components use the standard flight time method.

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Intel®440GX AGPset Design Guide

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Intel 440GX manual Placement & Layout, Post-Layout Simulation
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440GX specifications

The Intel 440GX chipset was launched in 1997 as part of Intel's series of chipsets known as the 440 family, and it served as a critical component for various Pentium II and Pentium III-based motherboard architectures. Specifically designed for the second generation of Intel’s processors, the 440GX delivered enhanced performance and supported a range of important technologies that defined PC architectures of its time.

One of the main features of the Intel 440GX was its support for a 100 MHz front-side bus (FSB), which significantly improved data transfer rates between the CPU and the memory subsystem. This advancement allowed the 440GX to accommodate both the original Pentium II processors as well as the later Pentium III chips, providing compatibility and flexibility for system builders and consumers alike.

The 440GX chipset included an integrated AGP (Accelerated Graphics Port) controller, which supported AGP 2x speeds. This enabled high-performance graphics cards to be utilized effectively, delivering many enhanced graphics capabilities for gaming and multimedia applications. The AGP interface was crucial at the time as it offered a dedicated pathway for graphics data, increasing bandwidth compared to traditional PCI slots.

In terms of memory support, the 440GX could address up to 512 MB of SDRAM, allowing systems built with this chipset to run comfortably with sufficient memory for the era’s demanding applications. The memory controller was capable of supporting both single and double-sided DIMMs, which provided versatility in memory configuration for system builders.

Another notable feature of the Intel 440GX was its support for multi-processor configurations through its Dual Processors support feature. This allowed enterprise and workstation computers to leverage the performance advantages of multiple CPUs, making the chipset suitable for business and professional environments where multitasking and high-performance computing were essential.

On the connectivity front, the chipset supported up to six PCI slots, enhancing peripheral device integration and expansion capabilities. It also included integrated IDE controllers, facilitating connections for hard drives and CD-ROM devices.

Overall, the Intel 440GX chipset represented a balanced combination of performance, flexibility, and technology advancements for its time. Its introduction helped establish a foundation for subsequent advancements in PC technology and set the stage for more powerful computing systems in the years to come.
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