What is
Microcontroller
Microcontroller(sometimes
abbreviated µC, uC or MCU) is an integrated chip, it’s
also call as small computer/ embedded controller/ embedded systems.
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| AT89C51 Microcontroller |
It contains processor
core, memory(FLASH and RAM), input/output peripherals. Higher end
microcontroller contains ADC, watchdog timer and certain communication protocols.
Microcontrollers are
hidden inside a surprising number of products these days. If your microwave
oven has an LED
or LCD
screen and a keypad, it contains a microcontroller. All modern automobiles
contain at least one microcontroller, and can have as many as six or seven: The
engine is controlled by a
microcontroller, as are the anti-lock
brakes, the cruise control
and so on. Any device that has a remote control almost certainly contains a microcontroller: TVs, VCRs and high-end stereo
systems all fall into this category. Nice SLR and digital
cameras, cell phones,
camcorders,
answering
machines, laser
printers, telephones
(the ones with caller ID, 20-number memory, etc.), pagers, and feature-laden refrigerators,
dishwashers, washers
and dryers (the ones with
displays and keypads)...show in fig2.
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| Some peripheral interface to MC |
Oscillator frequency
is heart of the microcontroller. Without frequency it doesn’t process any
instruction, Some microcontrollers operate at clock rate
frequencies as low as 4 kHz, for low power consumption (single-digit mill watts or
microwatts).
