E
PENTIUM II XEON PROCESSOR AT 400 AND 450 MHZ
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12/15/98 5:14 PM 24377002.doc
2.3.1.
PENTIUM
II XEON PROCESSOR
V
CCCORE
Regulator solutions must provide bulk capacitance
with a low Effective Series Resistance (ESR) and
the system designer must also control the
interconnect resistance from the regulator (or VRM
pins) to the
330-contact slot
connector
. Simulation
is required. Bulk decoupling for the large current
swings when the part is powering on, or
entering/exiting low power states, is provided on the
voltage regulation module (VRM) defined in the
VRM 8.2 DC–DC Converter Design Guidelines and
the VRM 8.3 DC–DC Converter Design Guidelines.
The input to V
CCCORE
should be capable of
delivering a recommended minimum dI
CCCORE
/dt
defined in Table 6 while maintaining the required
tolerances defined in Table 5. See the Pentium
II
Xeon Processor Power DistributionGuidelines.
2.3.2.
LEVEL 2 CACHE DECOUPLING
Regulator
capacitance with a low Effective Series Resistance
(ESR) in order to meet the tolerance requirements
for V
CCL2
. Use similar design practices as those
recommended for V
CCCORE
. See the Pentium
II
Xeon Processor Power DistributionGuidelines.
solutions
need
to
provide
bulk
2.3.3.
SYSTEM BUS AGTL+ DECOUPLING
The Pentium II Xeon processor contains high
frequency decoupling capacitance on the processor
substrate; bulk decoupling must be provided for by
the system motherboard for proper AGTL+ bus
operation. High frequency decoupling may be
necessary at the
SC330
connector
to further
improve signal integrity if noise is picked up at the
connector interface. See the Pentium
II Xeon
Processor Power DistributionGuidelines.
2.4.
System Bus Clock and
Processor Clocking
The BCLK input directly controls the operating
speed of the system bus interface. All system bus
timing parameters are specified with respect to the
rising edge of the BCLK input, measured at the
processor core. The Pentium II Xeon processor
core frequency must be configured during Reset by
using the A20M#, IGNNE#, LINT[1]/NMI, and
LINT[0]/INTR pins (see Table 1). The value on
these pins during Reset determines the multiplier
that the Phase Lock Loop (PLL) will use for the
internal core clock. See the Pentium
Pro
Processor Family Developer’s Manualfor the
definition of these pins during reset and the
operation of the pins after reset.
NOTE
The frequency multipliers supported are
shown in Table 1; other combinations will not
be validated nor supported by Intel. Also,
each multiplier is only valid for use on the
product of the frequency indicated in Table 1.
Clock multiplying within the processor is provided
by the internal PLL, requiring a constant frequency
BCLK input. The BCLK frequency ratio cannot be
changed dynamically during normal operation or
any low power modes. The BCLK frequency ratio
can be changed when RESET# is active, assuming
that all Reset specifications are met.