Introduction to ARM

Introduction:

ARM: Advance RISC Machine

• ARM was established as a joint venture between Acorn,Apple and VLSI between Acorn, Apple and VLSI in November 1990.
• ARM is the industry's leading provider of 16/32-bit embedded RISC microprocessor solutions
• The company licenses its high-performance, low-cost, power-efficient RISC processors  peripherals  and system chip efficient RISC processors,peripherals,and system-chip designs to leading international electronics companies
• ARM provides comprehensive support required in developing a complete system.

Role of ARM :

• ARM Holdings is a technology company headquartered in Cambridge  England  UK Cambridge , England,UK.
• The company is best known for its processors, although it also designs, licenses and sells software development tools under designs,licenses and sells software development tools under the RealView and KEIL brands, systems and platforms, system-on-a-chip infrastructure and software.
• ARM do not make ICs
• ARM grant license of core to different silicon vendors like ATMEL, TI, STM etc
• These companies make ICs
• Examples are: KL25Z128VLK from freescale,  Atmel ATSAM3X8E , LM4F120 TI.

Where ARM processors are used:

• ARM processors can be used in any domain™
• Mainly ARM processors are used in Handheld devices,Robotics, Automation, Consumer Electronics.
• But ARM processors are available for almost every domain™.

ARM Based Products: Inside the processors

ARM Features:

• ARM are RISC (Reduced Instruction Set Computation) processor
• ARM is not 100 % RISC  some amendment to meets requirement of Embedded System
• Large Register file R0 to R16 (against RISC)
• Load and Store architecture - data processing is only in register contents
• Uniform and fixed length instructions
• 32 bit processor
• Good speed and power consumption ratio
• High code density
• Mostly single-cycle execution
• Speed 1Mhz to 1.25Ghz
• ARM support JAVA jezelle DBX (Direct Byte code execution)
• DSP Enhanced Instructions
• Support for TrustZone technology additional security core
• Conditional execution of all instructions (against RISC)
• 32 bit barrel shifter(against RISC)
• In build circuit for debugging

ARM Processor Family:

ARM7TDMI     

ARM9

ARM9TDMI

ARM9E

ARM10E

ARM11

Cortex

XScale

ARM Nomenclature:

ARMxyzTDMIEJFS

• X: series
• y: MMU
• z: cache
• T: Thumb
• D: debugger
• M: Multiplier : ARM processors has hardware multiplier unit doing multiplication
• I: Embedded ICE Macrocel: This is the hardware circuit which is used to generate traceinformation. This feature is used in advance debugging and very useful in bug fixing.
• E: Enhanced Instructions: Enhanced instruction set,may be for DSP
• J: Java acceleration by Jazelle: Hardware circuit which is used to run JAVA byte code
• F: Vector Floating-point : This is the hard wired implementaton of floating operations
• S :Synthesizable Version : It means ARM architecture can be modified. Because it will comes in terms of soft processor core

ARM Processor

ARM Processor Architecture (ARM core)

ARM Inside:

• ARM processor are widely used Embedded Systems
• ARM has good support of RTOS like Linux,QNX, VxWorks,FreeRTOS etc.
• ARM processor are best know for their low power consumptions and high end processing
• ARM has proprietary and open source development tools
• Proprietary tools:

•Windriver workbench

•Codesourcery

•Green Hills

•KEIL

•Realview

•IAR Workbench

• FreeOpen Source tools

•GNUARM

•Yagarto

Embedded ARM Development Tools:

ARM Development Tools include

•IDE

•Compiler  Suite

•Debugger

•Simulator

•JTAG Debugging Probe(Hardware)

•Development Board (Hardware)

• Both Open Source and Proprietary tools are available in market

Open Source | Freeware Tools:

IDE: Eclipse IDE (http://www.eclipse.org/)

Compiler Suite: GCC Compiler for ARM(http://www.gnuarm.com/) (http://www.yagarto.org/)

Debugger:GNU Debugger (http://www.gnu.org/software/gdb/)

Simulator: Insight Debugger (http://sourceware.org/insight/)

Proprietary Tools (1):

• IAR Workbench for ARM(http://www.iar.com/)
• Complete toolchain including IDE, Compiler, Debugger,Simulator
• Evaluation / Kickstart version are available for free download
• IAR also provide IAR PowerPac RTOS for ARM

Proprietary Tools (2):

• Keil for ARM(http://www.keil.com/arm/)
• Complete toolchain include uvision IDE,Compiler(armcc),Debugger and Simulator
• KEIL also provide RTX RTOS for ARM
• Evaluation version is also available for download

JTAG Debugging Probe:

• Olimex (http://www.segger.com/cms/jlink.html)
• This is USB Powered JTAG In circuit emulator
• This can be used with various tools like IAR, KEIL, Sourcery++ etc
• Generally ARM JTAG Debugger is a 20 Pin Interface

RTOS for ARM | Proprietary

• Vxworks from Windriver         ( http://www.windriver.com/)
• Threadx from Express Logic    ( http://www.rtos.com/)
• μC/OS II from Micrium            ( http://micrium.com)
• Montavista Linux from Montavista( http://www.mvista.com)
• QNX from QNX software system   (http://www.qnx.com/)

RTOS for ARM | Free and Open Source

• Linux       (https://www.rtai.org/)
• uClinux   (http://www.uclinux.org/)
• Ecos      (http://ecos.sourceware.org/)
• CooCox  (http://www.coocox.org)
• freeRTOS  (http://www.freertos.org/)