By Andrew Gliga Cs 147

What are Embedded Systems? Similar to real computers  They have CPU, memory, I/O Though they have limited tasks  Can only do specific things that they are designed for No specific definition for Embedded Systems, some systems have one task, others have hundreds. Some have GUI, some do not even have a mode of interaction

What uses Embedded Systems? Cars, Airplanes, Coffee Machines, MP3 players, cellphones  Basically any machine that needs to perform certain tasks The Embedded Systems in these machines controls certain aspects, such as fuel injection, pilot controls, speedometers, and dispensing Coffee

History of Embedded Machines Computers in the 1940's were too large and expensive to be used in portable tasks, even though they could perform simple tasks. Over time though, with smaller and smaller computers, they could be created for specific tasks

More History Charles Stark Draper developed the first modern Embedded Machine for the Apollo Spacecraft, called the Apollo Guadance computer that helped make the Moon landing possible.

Even More History With the introduction of the Microprocessor, Embedded Machines were able to take smaller and smaller forms. This allows smaller and lighter machines that control many of our devices today, such as our Cell phones, or MP3 players

Characteristics They can only be used for specific tasks, not general tasks They run with limited resources They can also be a part of a larger system and used as a subsystem  For example: a car is the larger system, while the Embedded System is a subsystem of the car

Microcontrollers Microcontrollers is what controls the embedded system Unlike Microprocessors, they include memory and I/O. In a sense, they are like a mini computer  They implement AND, OR, XOR, NOT gates  Extremely compact and cheap

Microcontrollers are Small

Aspects of Microcontrollers Watchdog timers  They generally keep an eye on the system.  When an error occurs in the system they enable a failsafe mechanism.  Similar as a human resets a non- responsive machine, the Watchdog timer automatically 'resets' the Microcontroller to a normal state when it doesn't respond normally for a specified time

Systems on a Chip (SOC) Microcontrollers, while they are mini computers still require supporting circuits.  Examples: Decoders, signal converts, or signal processors SOC incorporates all these suporting circuits and a Microcontroller in one easy and compact chip.  They are fast, small, and compact. They even consume less memory than having all the other chips that they replace

Embedded Software Software written for an embedded machine needs to have the specs of the machine in mind. The software is built in the Embedded System itself Software also can not be fine tuned after the program is embedded onto the circuit  Need to get it right the first time!

Embedded Systems Memory The Embedded System does not use virtual memory, since it relies on being quick. Embedded programmers have to be aware of the size of memory, since it is limited based on the machine

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