A BRIEF HISTORY OFEMBEDDED SYSTEM INTRODUCTION • What is meant by a system ? • What is embedded system ? • What are the components in the embedded system? • Examples of embedded system. . . . which makes it a system in dedicated for an application (s) or specific part of an application or product or part of a larger system. • · Embedded system is a single purpose computer built in to larger system for processing the control and monitoring the system. .EMBEDDED SYSTEM • Embedded system is a system that has computer.hardware and embedded software. . the embedding system ..Cont. • Embedded System: A computer which is integrated into another system. Features of an embedded system • components of embedded computer: hardware and software • Timeliness: controller must be able to respond fast enough to keep its operation within a safe region • System interconnection • Reliability . .EMBEDDED SYSTEM CONSTRAINTS An embedded system is designed to keep in view three constraints: – Available system memory – Available processor speed – The need to limit the power dissipation When running the system continuously in cycles of wait for events. run. stop and wakeup and sleep. .COMPONENTS OF EMBEDDED SYSTEM • It has Hardware Processor. Timers. • It has Real Time Operating System (RTOS) RTOS defines the way the system work. It sets the rules during the execution of the application program. Ports. Memories. Which supervise the application software. Interrupt controller. I/O Devices. A small scale embedded system may not need an RTOS. • It has main Application Software Which may perform concurrently the series of tasks or multiple tasks. etc. . halt. Fetch Execution Unit (EU) Execute.Processor • Processor is the heart of the embedded system. interrupt and jump or another set of instructions • Processor runs the cycle of fetch and execute. It consists of two units: • Two Essential Units: Operations Control Unit (CU). processor mostly in the form of IC or in the form of Core ASIP [Application Specific Instruction Processor] or Soc [System on Chip]. . core means a part of functional circuit on VLSI chip.It includes ALU and executes the program task. say. ...Cont.graphics processor.pixel coprocessor etc. • An embedded system processor chip or core can be one of the following General purpose processor [GPP] Microrpocessor Microcontroller single purpose processor: coprocessor. .Cont.. • Application Specific System Processor [ASSP] • Multipurpose system using general purpose processor [GPPs] • GPP CORE or ASIP core integrated in to an ASIP or VLSI[Very Large Scale Integrated circuit] or FPGA[Fast Programmable Gate Array] integrated with processor units in the VLSI chip. OR • Charge pump concept used in a system of little power needs. or 2.Embedded HW units and devices in a system • Power supply 1. Supply from a system to which the embedded system interfaces. for examples. clock. System own supply with separate supply rails for IOs. basic processor and memory and analog units. for example in a network card. in the mouse or contact less smart card . Real Time Clock*( System Clock) and Timers driving hardware and software . Appropriate clock oscillator circuit 2.Cont.. (ii) Clock Oscillator Circuit and Clocking Units 1. Reset on Power-up 2. External and Internal Reset circuit 3.. (iii) Reset Circuit 1. Reset on Timeout of Watchdog timer • MEMORY .Cont. DAC g. Keypad or Keyboard IO Interface d. GPIB Interface Element h. ADC – Single or Multi channel f. Modem and j. Communication Driver(s) Network Ethernet or serial driver to communicate with host embedded system Expansion b. . 802. Media IO Control Element c.IO Communication Unit a. IrDA. Bluetooth. Pulse Dialing Element i. LCD Display System Interface e.11. IO interrupts. timer and RTC interrupts.Interrupts Handler • Interrupt Handling element for the external port interrupts. software interrupts and Exceptions. . • Software in high level language. • Software for concurrent processing and scheduling of multiple tasks and ISRs using RTOS.Embedded software in a system • Coding in a machine code. . • Software in processor specific assembly language. . Note: specific to the microcontroller or processor used . . . And the list goes on and on . Low cost. low power.always a digital camera Tightly-constrained -. small.a digital camera • • • Single-functioned -.only to a small extent .An embedded system example -. fast Reactive and real-time -.
Report "A Brief History of Real Time Embedded System"