The Unabridged Pentium 4 IA32 Processor Genealogy

Introduction

One of the keys to a high-speed signaling environment is to utilize a low-voltage swing (LVS) to change the state of a signal from one state to the other. The P6 and Pentium® 4/M (i.e., Pentium® 4 and Pentium® M) FSB falls into this category. It permits the operation of the FSB at speeds of 200MHz or higher. The FSB is implemented using a modified version of the industry standard GTL (Gunning Transceiver Logic) specification, referred to by Intel® as AGTL+ (Assisted GTL+). The spec has been modified to provide larger noise margins and reduce ringing. This was accomplished by using a higher termination voltage and controlling the edge rates. The net result is that the FSB supports more electrical loads (currently up to eight devices) ...