E
SIGNAL QUALITY SPECIFICATIONS
9-3
8/27/97 1:16 PM CH09.DOC
INTEL CONFIDENTIAL
(until publication date)
9.2.
GTL+ SIGNAL QUALITY SPECIFICATIONS
Table 9-2 and Figures 8-3 and 8-4 describe the GTL+ signal quality specifications for the
Pentium II processor.
Table 9-2. GTL+ Signal Groups Ringback Tolerance
T#
Parameter
Min
Unit
Figure
Notes
α
:
Overshoot
100
mV
8-3, 8-4
1, 2
τ
:
Minimum Time at High
1.5
ns
8-3, 8-4
1, 2
ρ
:
Amplitude of Ringback
–250
mV
8-3, 8-4
1, 2, 3
φ
:
Final Settling Voltage
250
mV
8-3, 8-4
1, 2
δ
:
Duration of Sequential Ringback
N/A
ns
8-3, 8-4
1, 2
NOTES:
1.
Specified for the edge rate of 0.3 – 0.8 V/ns. See Figure 9-2 for the generic waveform.
2.
All values specified by design characterization.
3.
Ringback below V
REF
+250 mV is not supported.
9.3.
NON-GTL+ SIGNAL QUALITY SPECIFICATIONS
Many scenarios have been simulated to generate a set of GTL+ layout guidelines which are
available in the Pentium
®
II Processor GTL+ Guidelines (Order Number 243330). There are
three signal quality parameters defined: Overshoot/Undershoot, Ringback and Settling Limit.
All three signal quality parameters are shown in Figure 9-2 for non-GTL+ signal groups.
9.3.1.
Overshoot/Undershoot Guidelines
Overshoot (or undershoot) is the absolute value of the maximum voltage above the nominal
high voltage or below V
SS
. The overshoot/undershoot guideline limits transitions beyond
V
CC
or V
SS
due to the fast signal edge rates. (See Figure 9-2 for non-GTL+ signals.) The
processor can be damaged by repeated overshoot events on 2.5V tolerant buffers if the charge
is large enough (i.e., if the overshoot is great enough). However, excessive ringback is the
dominant detrimental system timing effect resulting from overshoot/undershoot (i.e.,
violating the overshoot/undershoot guideline will make satisfying the ringback specification
difficult). The overshoot/undershoot guideline is 0.8V and assumes the absence of diodes on
the input. These guidelines should be verified in simulations without the on-chip ESD
protection diodes present because the diodes will begin clamping the 2.5V tolerant signals
beginning at approximately 1.25V above Vcc
CORE
and 0.5V below V
SS
. If signals are not
reaching the clamping voltage, this will not be an issue. A system should not rely on the
diodes for overshoot/undershoot protection as this will negatively affect the life of the
components and make meeting the ringback specification very difficult.
Содержание Pentium II
Страница 1: ...D Pentium II Processor Developer s Manual 243502 001 October 1997 1997...
Страница 11: ...E 1 Component Introduction...
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Страница 17: ...E 2 Micro Architecture Overview...
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Страница 33: ...E 3 System Bus Overview...
Страница 34: ......
Страница 45: ...E 4 Data Integrity...
Страница 46: ......
Страница 51: ...E 5 Configuration...
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Страница 63: ...E 6 Test Access Port TAP...
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Страница 75: ...E 7 Electrical Specifications...
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Страница 107: ...E 8 GTL Interface Specifications...
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Страница 129: ...E 9 Signal Quality Specifications...
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Страница 137: ...E 10 Thermal Specifications and Design Considerations...
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Страница 149: ...E 11 S E C Cartridge Mechanical Specifications...
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Страница 154: ...S E C CARTRIDGE MECHANICAL SPECIFICATIONS E 11 4 001055a Figure 11 2 S E C Cartridge Top and Side Views...
Страница 155: ...E S E C CARTRIDGE MECHANICAL SPECIFICATIONS 11 5 001054a Figure 11 3 S E C Cartridge Bottom Side View...
Страница 173: ...E 12 Boxed Processor Specifications...
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Страница 185: ...E 13 Integration Tools...
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Страница 203: ...E 14 Advanced Features...
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Страница 207: ...E A Signals Reference...
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