Transcript Embedded System Lab

Embedded System Lab
What is an embedded systems?
• An embedded system is a computer system designed for
specific control functions within a larger system, often
with real-time computing constraints. It is embedded as part of
a complete device often including hardware and mechanical
parts. By contrast, a general-purpose computer, such as
a personal computer (PC), is designed to be flexible and to
meet a wide range of end-user needs. Embedded systems
control many devices in common use today.
Processor
• Processor is an important unit in the
embedded system hardware. It is the heart of
the embedded system.
• microcontroller market
over 20 billion devices per year in 2010.
What Is the ARM Cortex-M3 Processor?
• Greater performance effi ciency, allowing more work to be done without increasing
thefrequency or power requirements
• Low power consumption, enabling longer battery life, especially critical in portable
products including wireless networking applications
• Enhanced determinism, guaranteeing that critical tasks and interrupts are serviced
as quickly as possible but in a known number of cycles
• Improved code density, ensuring that code fi ts in even the smallest memory
footprints
• Ease of use, providing easier programmability and debugging for the growing
number of 8-bit and 16-bit users migrating to 32-bit
• Lower-cost solutions, reducing 32-bit-based system costs close to those of legacy 8bit and 16-bit devices and enabling low-end, 32-bit microcontrollers to be priced
at less than US$1 for the first time
• Wide choice of development tools
Background of ARM and ARM
Architecture
• The Cortex-M3 processor is the central processing unit (CPU)
of a microcontroller chip. In addition, a number of other
components are required for the whole Cortex-M3 processorbased microcontroller. After chip manufacturers license the
Cortex-M3 processor, they can put the Cortex-M3 processor in
their silicon designs, adding memory, peripherals,
input/output (I/O), and other features.
• ARM was formed in 1990 as Advanced RISC Machines Ltd., a
joint venture of Apple Computer, Acorn Computer Group, and
VLSI Technology.
This business model is commonly called intellectual
property (IP)licensing.
• Unlike many semiconductor companies, ARM does not manufacture
processors or sell the chips directly. Instead, ARM licenses the
processor designs to business partners, including a majority of the
world’s leading semiconductor companies. Based on the ARM lowcost and power-efficient processor designs, these partners create
their processors, microcontrollers, and system-on-chip solutions.
• ARM （Advanced RISC Machine）: British company
• RISC (Reduced instruction set computing)
In 2011 alone, producers of chips based on ARM architectures reported
shipments of 7.9 billion ARM-based processors, representing 95%
of smartphones, 90% of hard disk drives, 40% of digital
televisions and set-top boxes, 15% of microcontrollers and 20%
of mobile computers.
ARM Version 7
• (Cortex-A): Application processors required to run complex applications
such as high-end embedded operating systems (OSs), such as Symbian, Linux, and
Windows Embedded, requiring the highest processing power, virtual memory system
support with Memory Management Units (MMUs), and, optionally, enhanced Java
support and a secure program execution environment. Example products include
highend mobile phones and electronic wallets for fi nancial transactions.
• (Cortex-R): Real-time, high-performance processors targeted primarily
at the higher end of the real-time1 market—those applications, such as high-end
breaking systems and hard drive controllers, in which high processing power and high
reliability are essential and for which low latency is important.
• Cortex-M): Processors targeting low-cost applications in which
processing effi ciency is important and cost, power consumption, low interrupt latency,
and ease of use are critical, as well as industrial control applications, including
realtime control systems.
Target Applications of Stellaris family
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Stellaris family are produced by Luminary Company , which is bought by TI
They are positioned for cost-conscious applications requiring significant control
processing and connectivity capabilities such as:
■ Gaming equipment
■ Network appliances and switches
■ Home and commercial site monitoring and control
■ Electronic point-of-sale (POS) machines
■ Motion control
■ Medical instrumentation
■ Remote connectivity and monitoring
■ Test and measurement equipment
■ Factory automation
■ Fire and security
■ Lighting control
■ Transportation
Cortex-M3
Register
Bank
ALU
Trace Interface
Decoder
Interrupts
Instruction
Fetch unit
Interrupt Controller
(NVIC)
Processor Core System
Trace
Memory Interface
Instruction Bus
Memory
Protection
System
Data Bus
Debug
Interface
Bus Interconnect
Code
Meomory
Debug
System
Memory System
and Perpherals
Private
Perpherals
Optional
Debug
Name
Functions(and Banked Registers)
R0
General-Purpose Register
R1
General-Purpose Register
R2
General-Purpose Register
R3
General-Purpose Register
R4
General-Purpose Register
R5
General-Purpose Register
R6
General-Purpose Register
R7
General-Purpose Register
R8
General-Purpose Register
R9
General-Purpose Register
R10
General-Purpose Register
R11
General-Purpose Register
R12
General-Purpose Register
Low Register
R13(MSP)
R13(PSP)
High Register
Main Stack Pointer(MSP),Process Stack Pointer(PSP)
R14
Link Register(LR)
R15
Program Counter(PC)