Acorn ARM2

The ARM2 implementation documented by Acorn: three pipeline stages and a 2 µm CMOS process. Introduction timing and unverified ISA/cache fields remain separate from checked facts.

ARM2ARM 2Acorn microarchitectures arm2

Specifications

17 SOURCE-LINKED FIELDS

Identity & fabrication
Process	Published analysisSteve Furber; Springer-Verlag London (1995); author copy hosted by ResearchGate Matching source values (1) 2 µm · ChipsWiki / WikiChip contributors Acorn/microarchitectures/arm2 · revision 17582 · {{microarchitecture}} / process · Shared upstream; not independent confirmation. Scope: architecture Source date: 1995 Only this archived field was corroborated; see source-specific verification limits.
Introduction date	UnconfirmedWikiChip contributors · Internet Archive capture Scope: architecture Archived value 1986 is retained in recovery evidence but remains uncorroborated. The author’s 1987 first-sample date describes a different event.
Architecture name	Published analysisChipsWiki / WikiChip contributors Scope: architecture Source date: 2018-07-10 Source-reported parameter; source revision 2018-07-10. Not an independent measurement.
Foundry	Published analysisChipsWiki / WikiChip contributors Scope: architecture Source date: 2018-07-10 Source-reported parameter; source revision 2018-07-10. Not an independent measurement.
Foundry	Published analysisChipsWiki / WikiChip contributors Scope: manufacturer 2 Source date: 2018-07-10 Source-reported parameter; source revision 2018-07-10. Not an independent measurement.
Introduction	Published analysisChipsWiki / WikiChip contributors Scope: architecture Source date: 2018-07-10 Source-reported parameter; source revision 2018-07-10. Not an independent measurement.
Architecture core count	Published analysisChipsWiki / WikiChip contributors Scope: architecture Source date: 2018-07-10 Source-reported parameter; source revision 2018-07-10. Not an independent measurement.
ISA	Published analysisChipsWiki / WikiChip contributors Scope: architecture Source date: 2018-07-10 Source-reported parameter; source revision 2018-07-10. Not an independent measurement.
Architecture predecessor	Published analysisChipsWiki / WikiChip contributors Scope: architecture Source date: 2018-07-10 Source-reported parameter; source revision 2018-07-10. Not an independent measurement.
Architecture successor	Published analysisChipsWiki / WikiChip contributors Scope: architecture Source date: 2018-07-10 Source-reported parameter; source revision 2018-07-10. Not an independent measurement.
CPU & clock domains
CPU execution type	Published analysisChipsWiki / WikiChip contributors Scope: architecture Source date: 2018-07-10 Source-reported parameter; source revision 2018-07-10. Not an independent measurement.
CPU execution type	Published analysisChipsWiki / WikiChip contributors Scope: type 2 Source date: 2018-07-10 Source-reported parameter; source revision 2018-07-10. Not an independent measurement.
CPU pipeline stages	Published analysisChipsWiki / WikiChip contributors Scope: architecture Source date: 2018-07-10 Source-reported parameter; source revision 2018-07-10. Not an independent measurement.
CPU decode width	Published analysisChipsWiki / WikiChip contributors Scope: architecture Source date: 2018-07-10 Source-reported parameter; source revision 2018-07-10. Not an independent measurement.
Additional specifications
Designer	Manufacturer / primary sourceVLSI Technology, Inc.; original manual scan hosted by Bitsavers Matching source values (1) Acorn Computers · ChipsWiki / WikiChip contributors Acorn/microarchitectures/arm2 · revision 17582 · {{microarchitecture}} / designer · Shared upstream; not independent confirmation. Scope: architecture Source date: 1990 Only this archived field was corroborated; see source-specific verification limits.
Pipeline stages	Manufacturer / primary sourceAcorn Computers; original manual scan hosted by 4corn Scope: architecture Only this archived field was corroborated; see source-specific verification limits.
First functional samples (author account)	Published analysisSteve Furber; Springer-Verlag London (1995); author copy hosted by ResearchGate Scope: architecture Source date: 1995 Sample delivery year in Furber’s retrospective; not a verified product introduction date.

THE VISUAL EVIDENCE

Visual sources

0 DOCUMENTED SOURCES

Help document this silicon.

We have not yet identified a reliable public visual source for this record. Suggest a die photograph, package image, paper or manufacturer diagram.

TECHNICAL ARTICLE

ARM2: a short pipeline and a careful historical record

Three corroborated archive fields, with unresolved claims left visible.

VLSI Museum synthesis of the cited sources. · 2026-09-07

Overlapping three stages

Acorn’s ARM2 datasheet extract describes one instruction executing while following instructions are decoded and fetched. VLSI’s manual explicitly names three stages. This explains overlap between instructions; it does not establish a fixed completion rate for every instruction or memory access.

PRIMARY SOURCEVLSI Technology, Inc.; original manual scan hosted by Bitsavers Acorn Computers; original manual scan hosted by 4corn

Samples and introduction are different events

Steve Furber’s retrospective describes ARM2’s move to 2 µm CMOS and functional samples in 1987. The archived WikiChip infobox says introduction in 1986. Museum interpretation: these event labels require separate evidence, so the introduction date stays unresolved rather than being replaced automatically.

PUBLISHED ANALYSISSteve Furber; Springer-Verlag London (1995); author copy hosted by ResearchGate WikiChip contributors · Internet Archive capture

Follow the documented connections

Follow the connections

6 SOURCE-LINKED RELATIONSHIPS

Source documentAcorn RISC Machine Family Data Manual (1990)document

VLSI Technology, Inc.; original manual scan hosted by Bitsavers · Evidence

Source documentAcorn Assembler Release 2 — Appendix D, ARM datasheetdocument

Acorn Computers; original manual scan hosted by 4corn · Evidence

Source documentComputing without Clocks: Micropipelining the ARM Processordocument

Steve Furber; Springer-Verlag London (1995); author copy hosted by ResearchGate · Evidence

Designed byAcorn Computerscompany

VLSI Technology, Inc.; original manual scan hosted by Bitsavers · Evidence

Referenced by · implements architectureVL86C010sku

Explicit microarch infobox parameter; exact architecture identity match.

ChipsWiki / WikiChip contributors · Evidence

Referenced by · implements architectureVL2333sku

Explicit microarch infobox parameter; exact architecture identity match.

ChipsWiki / WikiChip contributors · Evidence

Sources and historical context

ARM2 - Microarchitectures - Acorn (archived WikiChip)

WikiChip contributors · Internet Archive capture · third-party-report · archive-identity-verified; facts require separate corroboration

ORIGINAL PAGE: ARM2 - Microarchitectures - Acorn
ARCHIVE CAPTURE: 20201124125451
VERIFICATION: archive-verified · MediaWiki title / page id / revision; scalar infobox rows identified by their field labels

Acorn RISC Machine Family Data Manual (1990)

VLSI Technology, Inc.; original manual scan hosted by Bitsavers · official-disclosure · Indexed original-scan excerpts checked: Preface p. ix and Introduction p. 1-8. Full PDF retrieval was unavailable; no manual images acquired.

Acorn Assembler Release 2 — Appendix D, ARM datasheet

Acorn Computers; original manual scan hosted by 4corn · official-disclosure · Indexed scan text checked at printed p. 191: explicitly ARM2, with reference to VL86C010. Full PDF exceeded browser size limit; publication year not verified.

Computing without Clocks: Micropipelining the ARM Processor

Steve Furber; Springer-Verlag London (1995); author copy hosted by ResearchGate · third-party-report · Author-uploaded text checked in section 5; uploader attribution to Steve Furber visible. Publisher identity and 1995 date confirmed at https://link.springer.com/chapter/10.1007/978-1-4471-3575-3_5 . Primary participant account, not a contemporaneous release notice. No reuse grant asserted.

ARM2 — ChipsWiki, revision 17582

ChipsWiki / WikiChip contributors · third-party-report · source linked