Debug Recommendations

4.3.2.1Debug Considerations

•As technology drives better low power modes, the VccCORE current demand could approach 0 Amps. This may cause a regulator to go out of regulation. Place pads for a load resistance on the VccCORE regulator in the event the regulator cannot approach 0 Amps.

•After meeting the guidelines in the Intel® Pentium® II Processor Datasheet, add as many extra high frequency and bulk decoupling capacitance sites as will fit near the processor slot.

•Intel recommends using industry standard Voltage Regulator Modules designed for the processor. However, previous VRM modules may not support future processors for Slot 1 unless built to VRM 8.2 specifications..

4.3.3Debug Layout

•Pay close attention to the keep out zones for the Logic Analyzer Interface (LAI). These keep out zones are required to ensure that the LAI can be installed within a system.

4.3.3.1Design Considerations

•Plan as much space as possible for the Intel® Pentium® additional cooling or other requirements for early Intel®

IIprocessor(s). This will allow for Pentium® II processor(s).

4.3.4Debug Procedures

•When using an ITP565 In-Target Probe for the processor a common error is that the boundary scan chain order in the ITP565.INI input file is not correct. Check the file to ensure that the scan chain connections on your motherboard match the order provided the tool in this file. This file needs to change based on what components are in the boundary scan chain. In DP systems, the processor with PREQ0# and PRDY0# is considered processor 0, even if it is not the first one in the chain. Processor 0 should be placed in its proper place in the order.

•TCK noise may limit ITP speed or cause functional problems. Observe this signal with an oscilloscope. The TCK speed may be changed from 10MHz to 1250Hz using the keyword, TCLK = “value”, in the [Debug Port] section of the ITP565.INI file. See the ITP HELP menu “Changing the TCLK Signal Frequency” for the valid values. If you are having difficulty initializing the ITP562, try slowing TCK.

•ITP macros are available for the Intel® 440GX AGPset to assist in debugging your system. A number of macros are provided (e.g., utilities to read/write any PCI configuration register) a macro display POST codes and stop on a specified code, macros to dump the 82443GX and PIIX4E register sets as well as processor specific registers, etc.

•TDO out of each processor should have a 150 Ω pull-up. PICD0# and PICD1# should each have a 150Ω pull-up (IERR# might be asserted during the APIC/MP message generation if an insufficient pull-up is used.).

•Watch out for incorrect clock voltages. BCLK, TCK, and PICCLK are all Vcc2.5 signals.

•PICCLK must be driven even if APIC is not used. The APIC bus executes MP initialization even in a uni-processor system.

•APIC may be disabled in BIOS for initial debug by clearing bit 11 in the APIC base MSR (1Bh).

•Be sure boundary scan chains are properly reset using the TRST# pin of each device in the debug port chain.

Intel®440GX AGPset Design Guide

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Intel 440GX manual Debug Layout, Debug Procedures, Debug Considerations, Design Considerations
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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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