EV3 and EV4 Microprocessor

This document provides the technical specifications for the EV3 and EV4 microprocessors, which are the initial implementations of the ALPHA architecture. It details the chip features, micro-architecture components (Ibox, Ebox, Abox, Fbox), cache organization, pipeline structure, and privileged architecture library code (PALcode). Additionally, it describes the external interface signals, timing characteristics, and pinouts. Note that EV4 includes an on-chip floating-point unit and performance counters, while EV3 does not. The document covers specifications as of May 1991, with later update memoranda included for EV45 revisions.