Difference between micro processor and Micro controller

Thread Starter

yashowardhan

Joined Feb 12, 2010
8
Can anyone tell me the actual real time difference between a micro processor and a micro controller, along with their preferred areas of application?
 

rickmartin

Joined Sep 26, 2009
27
A microprocessor is a discrete digital component that processed data input according to the "instruction set" the processor is designed to use for making decisions. Your PC has a motherboard with the microprocessor at the heart of it with a host of support components necessary for the processor to work. A microcontroller is bascially a micro-computer, which included a microprocessor and a minimum of support components needed to make it work, including memory, input and output, and other components. A microcontroller can store a small program and is usually intended to perform a single function, such as a manufacturing process or running a small robot, whereas a microprocessor can perform a virtually endless array of functions, once it is built into a computer with the necessary support components. Hope this helps.
 

retched

Joined Dec 5, 2009
5,207
From Wikipedia:
http://en.wikipedia.org/wiki/Microcontroller

A microcontroller is a small computer on a single integrated circuit containing a processor core, memory, and programmable input/output peripherals. Program memory in the form of NOR flash or OTP ROM is also often included on chip, as well as a typically small amount of RAM. Microcontrollers are designed for embedded applications, in contrast to the microprocessors used in personal computers or other general purpose applications.
So a microcontroller contains a processor and other peripherals. A microprocessor needs many external peripherals.
 

sceadwian

Joined Jun 1, 2009
499
I think that's a good way to consider it.
Microprocessors generally require external controllers for complete functionality.
Microcontrollers tend to contain many of these otherwise external features internally, though many of them still have the ability to support a fairly wide variety of external devices and interfaces.
There really just words there's not hard line to differentiate, if you go a step further how do you clarify the difference between a micro controller and a System on Chip device? The general guidelines are just that, general guidelines, there are a lot of fuzzy area devices.
 

kubeek

Joined Sep 20, 2005
5,794
Another point of view could be that microcontroller is the part of (micro)processor which controls the inner operations and data transfers between registers, ALU and memory.
Or that part can simply be called controller, this kind of depends on the actual context of the word, microcontroller could refer to any other "small thing that controls other things".
Sorry if that confuses you even more :)
 

logicman112

Joined Dec 27, 2008
69
Microprocessors are used to realize general purpose computers.
Micro-controllers are used for embedded and electronic applications.

Computers are prepared for running several tasks(not time critical) simultaneously while each task has separate resources.

Micro-controllers in electronic mixed signal circuits are prepared for single task signal processing and control programs and functions mostly dealing with one specific time critical algorithm.
 

sceadwian

Joined Jun 1, 2009
499
Sorry logic, but every one of the generalities you layed out is so general there are applications on each side which contradict the general meaning =) Like I said, there are a lot of grey areas.
 

logicman112

Joined Dec 27, 2008
69
What i wrote is my several years of experience dealing with these components. Technical words have different definitions and depend on the taste and like of the person who defines them sometimes.

Micro indicates something very small, in range of micro meter, Processor means a circuit that processes , means general process.

Controller means an electrical circuit that controls something special. It is not normally used for general purpose computing from games, video to reading pdf format, to simulate an electronic circuit.

I know that micro-controllers sometimes use small task schedulers, like Texas or they may seem similar to microprocessors. But They normally do not access hard disk and the tasks are not swapped out to it! Like they do not have audit software subsystem to log some events or sophisticated cryptography.

Besides there is not segment protection to check tasks for limit and priority, no virtual address space or page tables. Besides microprocessors are mostly CISC with variable instruction cycles and complicated math functions like logarithm with single/double precision formats.
 

beenthere

Joined Apr 20, 2004
15,819
Besides there is not segment protection to check tasks for limit and priority, no virtual address space or page tables. Besides microprocessors are mostly CISC with variable instruction cycles and complicated math functions like logarithm with single/double precision formats.
That description is valid for a number of processors in modern computers. However, computers using Z80's, 6809's and 6502's had none of those features, but were considered microprocessors.

The dividing line is most obvious when you look at built-in I/O capabilities.

Look at the size of an IBM 370 and a 5150 - that is where the "micro" part comes in. Single IC processors were really micro compared to older computers.
 
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