04-01-2013, 04:36 PM
MICROCONTROLLER OVER MICROPROCESSOR
TRAINING INTRODUCTION
A microcontroller is a programmable logic and integrated circuit which can be programmed
to do a number of tasks. It is possible to control just about anything with the program written
by the user.Basically, a microcontroller (sometimes abbreviated μC, uC or MCU) is a small
computer on a single integrated circuit containing a processor core, memory, and
programmable input/output peripherals.
Some of the functions of a microcontroller are-
Ability to execute a stored set of instructions to carry out user defined task.
Ability to access external memory chips to read & write data from/to memory.
Ability to interface with the I/O devices.
Basic components of a Microcontroller are-
A CPU to execute programmed code
Memory, both RAM and ROM
Internal timers and input/output system, in form of i/o pins
Some Microcontrollers have some extra features like-
UART for serial communication, Internal EEPROM and PWM modules for analogue
outputMicrocontrollers are used in automatically controlled products and devices, such as
automobile engine control systems, implantable medical devices, remote controls, office
machines, appliances, power tools, toys and other embedded systems. By reducing the size
and cost compared to a design that uses a separate microprocessor, memory, and input/output
devices, microcontrollers make it economical to digitally control even more devices and
processes. Mixed signal microcontrollers are common, integrating analog components needed
to control non-digital electronic systems.
MICROCONTROLLER ARCHITECTURES
There are two types of basic architectures:
Von-Neumann Architecture- It has only one bus which is used for both data transfers and
instruction fetches, and therefore data transfers and instruction fetches must be scheduled -
they cannot be performed at the same time.
Harvard Architecture- It has physically separate signals and storage for code and data
memory. It is possible to access program memory and data memory simultaneously.
PIC16F877A MICROCONTROLLER
The PIC16F877a is one of the latest products from Microchip. It features all the components
which modern microcontrollers normally have. For its low price, wide range of application,
high quality and easy availability, it is an ideal solution in applications such as: the control of
different processes in industry, machine control devices, measurement of different values etc.