DIFFERENCE BETWEEN MICROCONTROLLER AND MICROPROCESSOR
The main reason for the development of microcontroller is to over come the only draw back of them icroprocessor. Even though microprocessor sare powerful devices, they require external chips like RAM, ROM, Input/Output ports and other components in order to desig a complete working system. This made it economically difficult to develop computerized consumer appliances on a large scale as the system cost is very high. Microcontrollers are the devices that actually fit the profile Computer — on —a chip as it consists of a main process in unit or processor along with some other components that are necessary to make it a complete computer. The components that are present on a typical microcontroller I Care CPU, memory, input/output ports and timers. The first microcontroller was developed in 1971 by Texas Instruments and is called TMS1000. It was made available for commercial use in 1974. The block diagram of a microcontroller is shown below.
Structure of Microcontroller
Microcontrollers are used to do the same assigned task repeatedly. Hence, the number of I/O ports and the amount of memory required is less compared to the microprocessor. Astoldearlier, in microcontroller external parts are integrated with CPU in a single chip and because of this integrated structure the overall size of them icrocontroller is smaller compared to them icroprocessor. In microcontroller you cannot modify the size of RAM, ROM and other components. Once a controller is designed the structure is fixed. So, the structure of them icrocontroller is not flexible
• Microprocessor is the hear to fComputersystem.
• It is only a processor, so memory and I/O components need to be connected externally
• Memory and I/O has to be connected externally, so the circuit becomes large.
• You can't use it in compact systems
• Cost of the entire system is high
• Due to external components, the total power consumption is high.
Therefore, it is not ideal for the devices running on stored power like batteries.
• Most of the microprocessors do not have power saving features.
• It is mainly used in personal computers
• Microprocessor has a smaller number of registers, so more
operations are memory - based.
• Microprocessors are based on VonNeumann model.
• It is a central processing unit on a single silicon - based integrated chip
• It has no RAM, ROM, Input - Output units, timers, and other
peripherals on the chip.
• It uses an external bus to interface to RAM, ROM, and other
• Microprocessor - based systems can run at a very high speed
because of the technology involved.
• It's used for general purpose applications that allow you to handle loads of data.
• It's complex and expensive, with a large number of instructions to process.
• APPLICATIONS OF MICROCONTROLLER
* Mobile phones
* CD/DVD players
* Washing machines
* Security alarms
* Keyboard controllers
* Microwave oven
* Mp3 players
• TYPES OF MICROCONTROLLER
* 8 bit Microcontroller
* 16 bit Microcontroller
* 32 bit Microcontroller
* Embedded Microcontroller
* External memory Microcontroller
A Microprocessor, popularly known as computer on a chip in its early days,
is a general purpose central processing unit (CPU) fabricated on a single
integrated circuit(IC) and is a complete digital computer (later
microcontroller is considered to be more accurate form of complete
computer). It is a small but very powerful electronic brain that operates at
a blistering speed and is of tenused to carry out instructions of a computer
program in order to perform arithmetic and logical operations, storing the data, system control, input/output operations etc. as per the instructions.
The key term in the definition of a microprocessor is general purpose.
It means that, with the help of a microprocessor, one can build a simple
system or a large and complex machine around it with a few extra
components as per the application. The main task of a microprocessor is
to accept data as input from input devices then process this data according
to the instructions and provide the result of these instructions as output
through output devices. Microprocessor is an example of sequential logic
device as it has memory internally and uses it to store instructions.
The first commercial Microprocessor was released by Intel in year 1971
November named as 4004(four — thousand — four). It is 4-bit
There are five important components in a microprocessor. They are
Arithmetic and LogicUnit(ALU), ControlUnit, Registers, Instruction
Decoder and Data Bus but the first three are considered significant
components. The blockdiagram of a microprocessor with the sebasic
components is shown below.
Structure of Microprocessor
The microprocessor is used in the very intensive processes. It only
contains a CPU(centralprocessingunit) but there are many other parts
needed to work with the CPU to complete a process. These all other
parts are connected externally. The microprocessor chip is not containing
all these parts internally. The number of external parts and the size of the
external parts depends on the application. Generally, it connected with
memory elements like RAM and ROM, I/O ports, timers, serial interface,
etc. The advantage of the microprocessor is that it has a flexible structure.
It means you can decide the size of RAM, ROM, number of I/O ports and
can modify all the things which are connected externally according to the
• It's complex and expensive, with a large number of instructions to
• MicroController has a processor a long with internal memory and
• Memory and I/O are already present, and the internal circuitis
• You can use it in compact systems
• Cost of the entire system is low
• As external components are low, total power consumption is less.
So it can be used with devices running on stored power like batteries.
• Most ofthe microcontrollers offer power-savingmode.
• It is used mainly in a washingmachine, MP3players, and embedded
• Microcontroller has more register. Hence the programs are easier
• Microcontrollers are based on Harvard architecture.
• It is a by product of the development of microprocessors with a
CPU along with other peripherals.
• It has a CPU a long with RAM, ROM, and other peripherals
embedded on a single chip.
• It uses an internal controlling bus.
• Microcontroller based systems run upto 200MHz or more
depending on the architecture.
• It's used for application - specific systems.
• It's simple and in expensive with less number of instructions to
• APPLICATIONS OF MICROPROCESSOR
* Accounting system
* Games machine
* Complex industrial controllers
* Traffic light
* Control data
* Military applications
* Defense systems
* Computation systems
• TYPES OF MICROPROCESSOR
* Complex Instruction Set Microprocessors
* The Application Specific Integrated Circuit
* Reduced Instruction Set Microprocessors
* Digital Signal Multiprocessors(DSPs)