ARM Processor Technology and Microcontrollers

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ARM Processor Technologyand Microcontrollers
Dave Upton, ARM LTD
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Brief History of
2008
..I gave them two things which National, Intel
and Motorola had never given their design teams
The first was no money The second was no
people. The only way they could do it (ARM) was
to keep it really simple." -- Hermann Hauser
1987
1990
Semiconductor IP (Intellectual Property)
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Today

• ARM designs technology that lies at the heart of
  advanced digital products

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Processor Portfolio

• World-class market-proven technology
• 20 processors for every application
• 200 silicon partners
• 500 licenses
• 10Bu shipped

ARMv7
ARMv6
ARMv5
ARMv4
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Profiles Segmenting the
Architecture
Cortex-A8, A9
Cortex-R4
A
M
R
Cortex-M3
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Microcontroller Market Today

• Traditional MCU market very fragmented
• 100s of silicon vendors
• Many different incompatible architectures
• Many vendors have multiple architectures which
  are incompatible
• Tools support varies widely
• Ecosystems required to encompass wide geographic
  and technical areas.

• Traditional application development can become
  difficult and expensive
• Incompatible architectures across organization
  reduces engineer efficiency
• Multiple tools chains required to support
  different architectures
• Poor code portability leads to continual
  re-invention of software

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Driving the Migration to 32-Bit
Improving Code Reuse

• Biggest single cost in product development
• System abstraction demands extra resources
• Savings from portable code offset device cost

• Continual feature growth in existing applications
• Complex algorithms require advanced math
• Increasing analysis at the node

Accelerating Time To Market
Device Aggregation

• Automatic code from meta-languages
• eg. Simulink, LabVIEW, UML, (C)
• Ease of use improvements

• Aggregation of DSP and MCU devices
• Multiple 8-Bit devices replaced with single
  32-Bit
• Substantially reduced BOM tool chains costs

Increasing System Connectivity

• MCUs increasingly connected
• USB, CAN, ENET, ZigBee, etc
• Potentially multiple comms channels per device
• Increasing complexity of stacks

• 32-Bit ARM devices now available for 1
• Extensive open source community
• Evaluation kits available for under 50

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Introduction to Cortex-M3 Processor

• Cortex-M3 Architecture
• High efficiency processor core 1.25 DMIPS/MHz
• Thumb-2 ISA
• Harvard bus architecture
• 3-stage pipeline with branch speculation
• Integrated bus matrix
• Configurable nested vector interrupt controller
  (NVIC)
• Advanced configurable debug and trace components
• Optional components for specific market
  requirements
• Memory Protection Unit (MPU)
• Embedded Trace Macrocell (ETM)
• Fault Robust Interface

Performance
100 ARM code
100 Thumb code
Code density
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ARM Cortex-M3 Designed for Ease of Use

• Write everything in C
• thumb2 means no veneer or mode change code
  required
• Simple programmers model
• Auto pushing / popping for ISRs
• Simplified register set
• Defined mem map
• Integrated SysTick timer reserved for RTOS
• Integrated NVIC
• Set priority levels
• ISR call chaining
• Lowest interrupt latency
• Excellent debug infrastructure
• more hw break points (8)
• Running system debug

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Interrupt Response Tail Chaining
ARM7TDMI Interrupt Handling
65 Saving Cycle Overhead
Cortex-M3 Interrupt Handling
ARM7TDMI
Cortex-M3

• 26 cycles from IRQ1 to ISR1
• (up to 42 cycles if in LSM)
• 42 cycles from ISR1 exit to ISR2 entry
• 16 cycles to return from ISR2

• 12 cycles from IRQ1 to ISR1
• (Interruptible/Continual LSM)
• 6 cycles from ISR1 exit to ISR2 entry
• 12 cycles to return from ISR2

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Typical Cortex-M3 based MCU device
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Increasing System Connectivity

• Increasing number of Software Stacks and
  Protocols already available on ARM based
  Industrial Microcontrollers
• Industrial Market reusing existing standards when
  possible to leverage development and software
  expertise
• Middleware availability and reuse becoming
  increasingly important
• Lack of object file standardization makes reuse
  more difficult
• Cannot link objects from different toolchains
• ABI compliance would allow better middleware
  reuse
• ARM is driving an initiative for ABI
  complianceto be adopted in other toolchains

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Cortex-M3 Processor Benefits

• Delivery of low-power cost-sensitive 32-bit
  devices with simplified development and reduced
  time to market

• Ease of use
• No assembler or interworking required
• Advanced debug and trace
• High performance
• Outstanding efficiency of 1.25 DMIPS/MHz
• Low power
• Low-power design
• Integrated sleep modes
• Lower cost devices
• 30 reduction in code memory with performance of
  ARM 32-bit code
• Smallest ARM processor

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ARM Cortex-M3 Broad Application Space
Traditional MCU Applications

• Low Gate Count Low Power
• Reduced Memory Requirements
• Fully Deterministic Interrupt Handling
• Integrated Sleep Modes
• Simplified Programmers Model

• Low cost
• Automotive Industrial Applications
• Bluetooth ZigBee
• Near Field Comms other PAN

Complex SoC Applications

• PC Peripherals (Biometric, User I/O)
• Application Specific Engines (MP3, etc.)
• Deterministic Sub-systems
• Supplementary Processing
• System Voltage Frequency Control

• High Processing Efficiency
• Exceptional Interrupt Handling
• Small Area in Advanced Geometries
• Superior Code Density

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Keil an ARM Company

• Leading supplier of MCU development tools
• ANSI C/C compilers, Debuggers
• Device simulation
• Middleware components
• Extensive Device Database
• gt1,400 8/16/32 bit MCUs
• Established support
• Web support portal.
• User group structure
• Global distribution network
• Huge installed base
• 100K users world wide

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Keil Microcontroller Development Kit
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ARM Ecosystem for Microcontrollers
Quality as well as Quantity Many of these third
parties identify ARM related business as largest
growth driver, which means robust, supported
solutions
and onwards to Modeling Solutions
Over 40,000 members on ARM-based MCU Forums
Nohau - Keil MDK distributors in Denmark, Sweden,
Norway, Finland
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Cortex-M3 - Success In Market



Over 20 licensees of Cortex-M3 processor Over 150
Cortex-M3 processor-based devices Over 400 ARM
processor-based MCUs 140 CAGR units shipped by
vendors (2006-2007)
Devices migrating to 32-bit
Intelligent toys
Under subscription
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Growth of ARM Based MCU

• 2007 2.4x rise in MCUs units shipped vs. 2006
• Highest volume contributor after wireless
  handsets
• RealView MDK sales increase shows long term
  success
• 2007 ARM MCU tool sales doubled in comparison
  with 2006
• Analysis for Industrial/Medical over next 5 years

Data provided by Semicast Industrial/Medical
Semiconductor Service (2008 Edition) Market
Analysis and Forecasts to 2013
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ARM Processor Technologyand Microcontrollers
Thank You
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Physical IP Support

• Combination of best in class ARM Artisan
  Physical IP and Cortex-M3 processor enables power
  and area optimized microcontroller
  implementations
• Specialized IP for 0.18µm Ultra-Low Leakage (ULL)
  process optimal for lowest leakage requirements
• Low-power, high density 7-track standard cell
  libraries
• About 20 area saving and over 20x leakage
  savings compared to mainstream library on
  generic process
• Custom 512x32 and 1024x32 single port RF memory
  instances
• Support byte write feature and multiple power
  down (with retention) modes
• Optimized for low dynamic and static power in
  minimum area
• Power Management Kit (PMK)
• Enables further reduction of leakage and dynamic
  power
• Supports power down modes with on-chip power
  gates combined with state retention for energy
  efficient wake-up

• Performance characteristics quoted for a 100MHz
  target
• implementation on the TSMC 0.18G process
• Does not include optional system peripherals
• (MPU ETM) or integration level components

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Fault Robust Observation Interface

• IEC61508 standard SIL3 certification
• Enables use in a variety of safety-critical
  applications in automotive, medical and military
  markets where Fault Robustness is an essential
  requirement.
• Certified by TUV SUD
• Fault Robust Implementation
• Optional interface port to enable integration
  with Yogitech Fault Robust technology (see
  http//www.fr.yogitech.com/)
• Enables standardized connection to fRCPU IP
• Zero gate count penalty if not implemented
• Zero impact on Cortex-M3 processor performance

fRFMEA analysis
fRDI
ARM Cortex-M3
fRCPU_armcm3
CM3 busses
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Low power implementation

• Cortex-M3 features architected support for sleep
  states
• Enables ultra low-power standby operation
• Critical for extended life battery based
  applications
• Includes very low gate count Wake-Up Interrupt
  Controller (WIC)

• Sleep
• CPU can be clock gated
• NVIC remains sensitive to interrupts
• Deep sleep
• WIC remains sensitive to selected interrupts
• Cortex-M3 inc. NVIC can be put into state
  retention
• WIC signals wake-up to PMU
• Cortex-M3 can be woken almost instantaneously
• React to critical external events

Power Management Unit
Cortex-M3
Wake-up
Deep Sleep
NVIC
WIC
Wake-up sensitive Interrupts
External interrupts
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Memory Map

• Very simple linear 4GB memory map
• Fixed map required to host system components and
  simplify implementation
• The Bus Matrix partitions memory access via the
  AHB and PPB buses

Bit-Banding Support
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ARM Cortex Family of Processors

• Bringing the benefits of architectural
• innovation across the spectrum
• ARM Cortex-A Series
• Applications processors for complex OSand user
  applications
• ARM Cortex-R Series
• Embedded processors for real-time signal
  processing and control applications
• ARM Cortex-M Series
• Deeply embedded processors optimized for
  microcontroller and low-power applications