Intel Pentium 4 Processor in the 478-PinPackage at 1.40 GHz, 1.50 GHz, 1.60 GHz, 1.70 GHz, 1.80 GHz, 1.90 GHz, and 2GHz

Introduction
8 Datasheet
Intel will be enabling support components for the Pentium 4 processor in the 478-pin
package including heatsink, heat sink retention mechanism, and socket. Manufacturability
is a high priority; hence, mechanical assembly can be completed from the top of the
motherboard and should not require any special tooling. The enabled components for the
478-pin package will be similar but different from the enabled components for the 423-pin
package due to package stackup differences.
The processor system bus uses a variant of GTL+ signalling technology called Assisted
Gunning Transceiver Logic (AGTL+) signalling technology.
1.1 Terminology
A ‘#’ symbol after a signal name refers to an active low signal, indicating a signal is in the
active state when driven to a low level. For example, when RESET# is low, a reset has
been requested. Conversely, when NMI is high, a nonmaskable interrupt has occurred. In
the case of signals where the name does not imply an active state but describes part of a
binary sequence (such as address or data), the ‘#’ symbol implies that the signal is
inverted. For example, D[3:0] = ‘HLHL’ refers to a hex ‘A’, and D[3:0]# = ‘LHLH’ also refers
to a hex ‘A’ (H= High logic level, L= Low logic level).
“System Bus” refers to the interface between the processor and system core logic (a.k.a.
the chipset components). The system bus is a multiprocessing interface to processors,
memory, and I/O.
1.1.1 Processor Packaging Terminology
Commonly used terms are explained here for clarification:
• Pentium
®
4 processor in the 478-pin package (also referred as the Processor)
— 0.18 micron Pentium 4 processor core in the FC-PGA2 package.
• Pentium
®
4 processor in the 423-pin package — 0.18 micron Pentium 4 processor
core in the PGA package.
• Processor — For this document, the term processor is the generic form of Pentium 4
processor in the 478-pin package.
• Keep-out zone — The area on or near the processor that system design can not
utilize.
• Intel
®
850 chipset— Chipset which supports RDRAM* memory technology for the
Pentium 4 processor in the 478-pin package.
• Intel
®
845 chipset— Chipset which supports PC133 and DDR memory technology
for the Pentium 4 processor in the 478-pin package.
• Processor core — Processor core die with integrated L2 cache.
• FC-PGA2 package — Flip-Chip Pin Grid Array package with 50-mil pin pitch and
Integrated Heat Spreader.
• mPGA478B socket — Surface mount, 478 pin, Zero Insertion Force (ZIF) socket with
50 mil pin pitch. Mates the processor to the system board.
• Integrated heat spreader —The surface used to make contact between a heatsink or
other thermal solution and the processor. Abbreviated IHS.