Introduction to Embedded. Programming with ... The Cortex-M Family is primarily
for low-power micro-controller applications. ... ARM Cortex-M3 Micro-controllers.
Introduction to Embedded Programming with ARM Cortex-M3 Alan Xiao, Ph.D Handheld Scientific, Inc.
[email protected]
Why ARM • ARM is a 32-bit RISC instruction set architecture developed by ARM Holdings. • Over 640 processor licenses sold to more than 200 companies • Over 17 billion ARM based chips shipped to date • ARM chips are used in 99% of the world’s cellphones, tablets and other mobile devices. • Microsoft announced support of ARM in Windows 8. • ARM Techcon conference held every year in Santa Clara
Copyright 2011 (c), Alan Xiao
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Latest ARM Family ARM Family
ARM Arch
ARM-Core
ARM9TDMI
ARMv4T
ARM9TDMI, ARM920T, ARM922T, ARM940T
ARM9E
ARMv5TE
ARM946E-S, ARM966E-S, RM968E-S, ARM966HS
ARMv5TEJ
ARM926EJ-S
XScale
ARMv5TE
XScale, Bulverde, Monahans
ARM11
ARMv6
ARM1136J(F)-S
ARMv6T2
ARM1156T2(F)-S
ARMv6ZK
ARM1176JZ(F)-S
ARMv6K
ARM11-MPCore
Cortex-A
ARMv7-A
Cortex-A8, Cortex-A9, Cortex-A15
Cortex-R
ARMv7-R
Cortex-M
ARMv6-M
Cortex-M0, Cortex-M1
ARMv7-M
Cortex-M3
ARMv7-ME
Cortex-M4
Copyright 2011 (c), Alan Xiao
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ARM Cortex A Family The Cortex-M Family is primarily for rich OS platforms such as smartphones and tablets ARM Core
Features
Application
Devices
Cortex-A8
600MHz – 1G
Smartphones, tablets, set-top boxes, etc.
Apple A4 (iPhone, iPad), Freescale iMX51, Qualcomm Snapdragon, TI OMAP3
Cortex-A9
Multi-core
Cortex-A15
1-2GHz Multicore
Apple A5, TI OMap4 Competing with x86 (Intel/AMD)
Copyright 2011 (c), Alan Xiao
A15 devices will be available Q4/2012 or early 2013.
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ARM Cortex-M Family The Cortex-M Family is primarily for low-power micro-controller applications.
ARM Core
Features
Application
Devices
Cortex-M0
Lowest power, smallest ARM MCU. Clock to 24MHz.
Low-end microcontroller
NXP LPC11xx
Cortex-M1
Developed Specifically for FPGA implementation
In FPGA
Soft Core for major FPGA: Altera, Xilinx, Actel.
Cortex-M3
High Performance MCU. Up to 120MHz
Mid to high-end micro-controller
NXP LPC17xx, ST Micro STM32
Cortex-M4
DSP Instructions. Memory Protection Unit. Up to 150MHz
High-end Computationintensive embedded applications
NXP LPC43xx (dual core M4/M0)
Copyright 2011 (c), Alan Xiao
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ARM Cortex-M3 Micro-controllers • They are micro-controllers – Micro-controllers: have everything in them (flash, ram, peripherals, etc.) – Micro-processors: usually need supporting chips (memory, peripheral bridges, etc.)
• From many different companies (NXP/Phillips, TI, Atmel, too many to list. See list in the tool). • Use the same core so they are essentially the same in the heart: learn one, use any. Copyright 2011 (c), Alan Xiao
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Cortex-M3 and Operating System • What operating systems can they run? – No Linux/WinCE/Android (since those normally require MMU). – Can run: uC/OSII (Micrium), FreeRTOS (freeRTOS.org), eCOSPro (eCosCentric), CMS (CMX Systems), etc.
• Carefully consider whether the application needs an OS: – Event driven model, SysTick, timer, watchdogs and DMA have powerful OS-like capability – OS adds cost and complexity. Hard to debug. – If the app really needs an OS, consider ARM9/ARM11.
Copyright 2011 (c), Alan Xiao
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Which Cortex-M3? • STM32 series from STMicroelectronics • Why? – Wide range of devices from low-cost (
