Mobile Intel Pentium 4 Processor - M and Intel 845MP/MZ Chipset Platform Design Guide

Mobile Intel

Pentium

4 Processor-M and Intel

845MP/845MZ Chipset Platform

Design Guide 25

3. Processor System Bus Design

Guidelines

3.1. Introduction

Intel’s Mobile Pentium 4 Processor-M is the first mobile Intel processor with the Intel NetBurst micro-

architecture. The Mobile Pentium 4 Processor-M utilizes Micro Flip-Chip Pin Grid Array (Micro-

FCPGA) package technology, and plugs into a 478-pin, surface-mount, Zero Insertion Force (ZIF)

socket, which is referred to as the mPGA478M socket. The Mobile Pentium 4 Processor-M maintains

full compatibility with IA-32 software. The Mobile Pentium processor’s 400-MT/s Intel NetBurst micro-

architecture system bus utilizes a split-transaction, deferred reply protocol like the Mobile Intel Pentium

4 Processor-M. The following layout guidelines support designs using the Mobile Intel Pentium 4

Processor-M and the Intel 845MP/845MZ chipset. Due to on-die Rtt resistors on both the processor and

the chipset, additional resistors do not need to be placed on the motherboard for most PSB signals. The

exception to these are RESET#, BPM[5:0]# signals which requires a 51.1 Ω ± 1% pull-up , and BR0

signal requires 220 Ω ± 5% pull-up to Vtt on the processor end of the transmission line.