BY ROGER NURSE

Open Hardware and Logic Circuits

Open Hardware

Open source hardware consists of physical artefacts of technology designed and offered by the open design movement (wiki definition) The term usually means that information about the

hardware is easily discerned Hardware design (i.e. mechanical drawings,

schematics, bills of material, PCB layout data, HDL source code and integrated circuit layout data), in addition to the software that drives the hardware, are all released with the FOSS approach.

Focus

Open hardware and logic circuits What are logic circuits?

How are they useful?

How are they designed?

The effect of open hardware on logic circuits

Hennessy and Patterson, MIPS and a strong case for open hardware

What are logic circuits?

Basis for the digital revolution

An abstraction of basic Boolean logic constructs

Circuits built upon implementations of the Boolean AND, OR and NOT functions

How are they useful?

How are they designed?

Simple digital circuits: Designed using simulating and implementation

software where chips are connected to build simple logic circuits

How are they designed?

Complex digital circuits: Designed primarily using a hardware description

language (HDL). Most popular HDLs are VHDL and Verilog. More complex and feature rich environments are used for design:

The Effect of Open Hardware on Logic Circuits

Freely available chip designs and schematics

Review of existing designs and possible improvement

Integration of existing designs into more complex and feature rich systems

Sky is the limit

Hennessy and Patterson, MIPS

Intel 4004, first commercial microprocessor and the rise of the complex instruction set computer (CISC)

Hennessy and Patterson, The birth of RISC and the creation of MIPS

Intel change of direction

Imagine the potential benefits if the Intel processor design information was readily available

Reference Material

The elements of computing systems, Noam Nisan and Shimon Schochken

Computer Organization and Design, John Hennessy and David Patterson

Digital Design and Computer Architecture, David Harris and Sarah Harris

Open Source Software - Wiki

BY ROGER NURSE

Questions and Comments