Intel Pentium M / Intel Celeron M Front Side Bus Strapping And Debug Port; Figure 27. Comp2 & Comp0 27.4-Ω Traces - Intel 855GM Design Manual

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Figure 27. COMP2 & COMP0 27.4-Ω Traces
PRIMARY SIDE
PRIMARY SIDE
COMP1
COMP2 COMP2
4.1.9. Intel Pentium M / Intel Celeron M Front Side Bus Strapping and
Debug Port
The Intel Pentium M / Intel Celeron M processor and GMCH both have pins that require termination for
proper component operation.
1. For the processor, a stuffing option should be provided for the TEST[3:1] pin to allow a 1 kΩ ±
5% pull-down to ground for testing purposes. For proper processor operation, the resistor should
not be stuffed. Resistors for the stuffing option on these pins should be placed within 2.0 inches of
the processor. For normal operation, these resistors should not be stuffed.
2. The processor's ITP signals, TDI, TMS, TRST and TCK should assume default logic values even
if the ITP debug port is not used. The TDO signal may be left open or no connect in this case. The
table below summarizes the default strapping resistors for these signals. These resistors should be
connected to the processor within 2.0 inches from their respective pins. It is important to note that
Table 18 is applicable only when neither the onboard ITP nor ITP interposer are planned to be
used. See Section 4.3 on cautions against designs with lack of debug tools support. Intel does not
recommend use of the ITP interposer debug port if there is a dependence only on the motherboard
termination resistors. The signals below should be isolated from the motherboard via specific
termination resistors on the ITP interposer itself per interposer debug port recommendations. For
the case where the onboard ITP700FLEX debug port is used refer to Section 4.3 for default
termination recommendations
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Intel 855GM/855GME Chipset Platform Design Guide
Intel Pentium M/Celeron M Front Side Bus Design Guidelines
COMP0
COMP0
18-mil Trace
18 -mil Dog Bone
COMP3
SECONDARY SIDE
SECONDARY SIDE
27.4 Ω 1% 27.4 Ω 1%
SECONDARY SIDE
COMP2 COMP2
COMP0
18 - mil Trace 18 - mil Trace
27.4 Ω 1% 27.4 Ω 1%
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