Design Checklist

•Poll the power button status bit during POST while SMIs are not loaded and go directly to soft- off if it gets set.

•Always install an SMI handler for the power button that operates until ACPI is enabled.

•Emergency Override: Pressing the power button for 4 seconds goes directly to S5.

•This is only to be used in EMERGENCIES when software is locked-up.

•This will cause user data to be lost in most cases.

•Do not promote pressing the power button for 4 seconds as the normal mechanism to power the machine off - this violates ACPI.

•To be compliant with the latest PC97 Specification, machines must appear off to the user when in the S1-S4 sleeping states. This includes:

•All lights except a power state light must be off.

•The system must be inaudible: Silent or stopped fan; drives are off.

•Note: Contact Microsoft* for the latest information concerning PC97 and Microsoft* Logo programs.

3.16Miscellaneous

•The 32 kHz oscillator is always required by the PIIX4/PIIX4E, even if the internal RTC is not used. Also, if the internal RTC in the PIIX4/PIIX4E is not used, an on board battery is not required at the PIIX4/PIIX4E, but is required for an external implementation of the RTC (e.g., RTC in the Super I/O). In this case, connect VCC(RTC) pin of the PIIX4/PIIX4E directly to 3VSB voltage.

•With the exception of GPI1, all unused GPIx inputs on the PIIX4E should be tied high through pull-up resistors (8.2K ohm - 10K ohm) to a power plane. Tying directly to the power plane is also acceptable. GPI1, if not used, should be tied to 3VSB through an 8.2K ohm resistor. If GPI1 is left floating, this will violate ACPI compliance by preventing the GPI_STS bit (register base + 0Ch, bit 9) from functioning properly. Note that GPI1 is tied to the resume well.

•To maintain RTC accuracy, the external capacitor values for the RTC crystal circuit should be chosen to provide the manufacturer’s specified load capacitance for the crystal when combined with the parasitic capacitance of the trace, socket (if used), and package, which can vary from 0pF to 8pF. When choosing the capacitors, the following equation can be used:

Specified Crystal Load = (Cap1 * Cap2)/(Cap1 + Cap2) + parasitic

capacitance

•The reference board uses 18pF capacitors and an Ecliptek EC38T crystal, which has a specified load of 12.5pF.

•When the PIIX4/PIIX4E internal RTC is used, ensure that the VBAT pin of the SMC Ultra IO device, FDC37932FR, is connected to ground through a pull-down resistor between 1K and 0 ohms. Consult your IO device vendor for implementation guidelines for this or other IO devices.

•Recommendations for New Board Designs to minimize ESD events that may cause loss of CMOS contents:

—Provide a 1uF X5R dielectric, monolithic, ceramic capacitor between the VCCRTC pin of the PIIX4/PIIX4E and the ground plane. This capacitor’s positive connection should not

Intel®440GX AGPset Design Guide

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Intel 440GX manual Miscellaneous
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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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