Timing Analysis, Term Description | Intel 440GX instruction

Motherboard Layout and Routing Guidelines

2.7Timing Analysis

To determine the available flight time window perform an initial timing analysis. Analysis of setup and hold conditions will determine the minimum and maximum flight time bounds for the host bus. Use the following equations to establish the system flight time limits.

Table 2-7. Intel® Pentium® II Processor and Inte® l 440GX AGPset System Timing Equations

Driver	Receiver				Equation

Pentium®II	AGPset	Tflight,min	≥ Thold	− Tco,min	+ Tskew,CLK + Tskew,PCB + Tclk ,max
processor	AGPset	Tflight,min	≥ Thold	− Tco,min	+ Tskew,CLK + Tskew,PCB + Tclk ,max
		Tflight ,max	≤ Tcycle − Tco,max − Tsu − Tskew,CLK − Tskew,PCB − Tjit − Tadj + Tclk,min
AGPset	Pentium®II	Tflight,min	≥ Thold	− Tco,min	+ Tskew,CLK + Tskew,PCB − Tclk ,min
AGPset	processor	Tflight,min	≥ Thold	− Tco,min	+ Tskew,CLK + Tskew,PCB − Tclk ,min

		Tflight,max	≤ Tcycle	− Tco,max − Tsu − Tskew,CLK − Tskew,PCB		− Tjit	− Tadj − Tclk ,max

Pentium®II	Pentium®II	Tflight ,min	≥ Thold − Tco,min		+ Tskew,CLK + Tskew,PCB
processor	processor	Tflight ,min	≥ Thold − Tco,min		+ Tskew,CLK + Tskew,PCB
		Tflight ,max	≤ Tcycle	− Tco,max − Tsu − Tskew,CLK − Tskew,PCB		− Tjit	− Tadj

The terms used in the equations are described in Table 2-8.

Table 2-8. Intel® Pentium® II Processor and Intel® 440GX AGPset System Timing Terms

Term	Description

Tcycle	System cycle time. Defined as the reciprocal of the frequency
Tflight,min	Minimum system flight time. Flight time is defined in Section 4, “Debug Recommendations” on
Tflight,min	page 4-1.
Tflight,max	Maximum system flight time. Flight time is defined in Section 4, “Debug Recommendations” on
Tflight,max	page 4-1.
Tco,max	Maximum driver delay from input clock to output data.
Tco,min	Minimum driver delay from input clock to output data.
Tsu	Minimum setup time. Defined as the time for which the input data must be valid prior to the input
Tsu	clock.
Th	Minimum hold time. Defined as the time for which the input data must remain valid after the input
Th	clock.
Tskew,CLK	Clock generator skew. Defined as the maximum delay variation between output clock signals
Tskew,CLK	from the system clock generator.
Tskew,PCB	PCB skew. Defined as the maximum delay variation between clock signals due to system board
Tskew,PCB	variation and Intel®440GX AGPset loading variation.
Tjit	Clock jitter. Defined as the maximum edge to edge variation in a given clock signal.
	Multi-bit timing adjustment factor. This term accounts for the additional delay that occurs in the
Tadj	network when multiple data bits switch in the same cycle. The adjustment factor includes such
Tadj	mechanisms as package and PCB crosstalk, high inductance current return paths, and
	simultaneous switching noise.

Tclk,min	Minimum clock substrate delay. Defined as the minimum adjustment factor that accounts for the
Tclk,min	delay of the clock trace on the Pentium II processor substrate.
Tclk,max	Minimum clock substrate delay. Defined as the maximum adjustment factor that accounts for the
Tclk,max	delay of the clock trace on the Pentium II processor substrate.

Intel®440GX AGPset Design Guide

2-17

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.

Intel 440GX manual Timing Analysis, Term Description

Models: 440GX

2.7Timing Analysis

Driver

Term

Description

from the system clock generator.

Intel®440GX AGPset Design Guide

440GX specifications