Intel Pentium 4 User Manual

System Bus Routing
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78 Intel
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Pentium
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4 Processor / Intel
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850 Chipset Family Platform Design Guide
5.4.1.12 Topology 9: Processor Voltage Regulator Sequencing Requirements
The Pentium 4 processor with 512KB L2 cache on .13 micron process requires a 1.2 V supply to
the VCCVID pin to support the on-die VID generation circuitry. The current requirements for this
voltage is 30 mA. A linear regulator is recommended to generate this voltage. The on-die VID
generation circuitry also has some power sequencing requirements. Figure 45 shows a block
diagram of a power sequencing implementation. Figure 46 and Figure 47 illustrate timing
diagrams of the power sequencing requirements.
5.4.1.13 VCCVID Regulator Recommendations
• The output of the voltage regulator used to generate VCCVID should be no more than
1.5 inches away from pin AF4 of the processor.
• The trace connecting the voltage regulator output to pin AF4 should be as wide as practical,
but not less than 0.025 inches.
• The trace connecting the voltage regulator output to pin AF4 should have both a 0.1 µF and
1.0 µF capacitor for decoupling. The 1.0 µF capacitor should be located as close as possible
to the output of the voltage regulator. The 0.1 µF capacitor should be located as close as
possible to pin AF4 on the processor.
• If an integrated voltage regulator such as the MIC5248 is used, the voltage input (pin 1)
should be connected to the system board’s VCC or 3.3 V rails through a zero ohm resistor.
The input of the voltage regulator should also be decoupled with a 0.1µF capacitor at the pin.
The trace connecting the voltage regular input to the zero resistor should be equal to or greater
than the voltage regulator output trace connected to the processor (i.e., if the connection to the
processor is 0.025 inches than the trace width to the input of the voltage regulator should be
0.025 inches or greater). The voltage regulator power good signal (pin 4) should be connected
to the voltage regulator output (pin 5) through a 10 kΩ resistor.
• During power-on the rising edge of the VCCVID power supply needs to be monotonic.
Examples of an acceptable monotonic and an unacceptable non-monotonic rising edge are
show below for reference.

Intel Pentium 4 Specifications

General

Architecture	x86
Core Count	1
Microarchitecture	NetBurst
Manufacturer	Intel
Core Names	Willamette, Northwood, Prescott, Cedar Mill
Virtualization Technology	No
Release Date	November 20, 2000
Clock Speed	1.3 GHz to 3.8 GHz
FSB Speed	400 MHz to 1066 MHz
Socket	Socket 423, Socket 478, LGA 775
Introduced	2000
Product Line	Pentium
Front Side Bus	400 MHz to 1066 MHz
Hyper-Threading	Yes (Prescott and later)
64-bit Support	Yes (Prescott and later)
Instruction Set	MMX, SSE, SSE2, SSE3
Discontinued	2008
Process Technology	180 nm, 130 nm, 90 nm, 65 nm
L2 Cache	256 KB, 512 KB, 1 MB, 2 MB
Lithography	180 nm, 130 nm, 90 nm, 65 nm
L1 Cache	8 KB