Basically, a microcontroller (µC) contains not only a processing unit but a small amount of memory (ROM, RAM, etc.), a few IO ports for peripherals, timer, etc. We can think of a microcontroller as a mini-computer. But a microprocessor (µP) contains only a processing unit which is quite powerful in terms of computing. To make use of microprocessor (µP), one needs extra hardware chips such as memory (RAM), peripheral boards, system bus, etc. It means that µP cannot be used stand-alone.
In that sense, a microcontroller can be called an SoC (System on Chip) that is built typically for embedded system use. One way to look at µC is a complete ‘Chip‘ that contains other necessary chips to perform a few specialized tasks which are characteristics of a typical embedded system. While µP is a processing unit ‘Chip‘ which is quite powerful and complex that is typically used for general purpose computing. Due to limited processing characteristics, µC is typically cheaper than µP. Besides, µC is typically quite compact when compared with µP. Examples of µC are the ARM Cortex-M series, Intel 8051, etc. Examples of µP are the ARM Cortex-A series, Intel Pentium series, etc.
We can find the use of µC in home appliances such as Washing machines, Ovens, etc. while we can find the use of µP in desktop computers, laptops, etc. It’s not the question of which one is better. Instead, it’s a question of what’s the need for a system. If someone is devising an embedded system where specific and customized tasks need to be done, picking µC is a typical choice. On the contrary, if someone is devising a general-purpose computing device, picking µP is a typical choice.
Let us see the differences in a tabular form that are as follows:
| Microcontroller |
Microprocessor |
| A microcontroller is a specialized form of a microprocessor |
The microprocessor is designed to be general-purpose. |
| It is cost-effective. |
It is a silicon chip |
| It is self-sufficient. |
It is a dependent unit |
| The microcontroller is used to perform a particular tasks. |
The Microprocessor is
used to perform a certain task. |
| Its power consumption is low. |
Its power consumption is high. |
It contains CPU, RAM, ROM,
Registers, Timer and input/output ports. |
It requires a combination of timers, controllers
memory chips. |
| Its size is smaller. |
Its size is larger. |
| It is a chip which is called single chip computer. |
It is a general purpose device which is called a CPU. |
| Microcontroller have no advantage of designing RAM, ROM, I/O port. |
It have advantages of versatility such that designer can decide the aount of RAM, ROM, I/O port as needed. |
| Its microprocessors processing power is lower than microprocessor. |
Its processing power is higher. |
| It uses Harvard Architecture. |
It uses Von Neumann Architecture. |
| It’s system cost is low. |
It’s system cost is high. |
| Each instruction needs an internal operation. |
Each instruction needs an external operation. |
| For Example- Television. |
For Example- Personal Computers. |
| Feature |
Microcontroller (µC) |
Microprocessor (µP) |
| Purpose |
Designed for specific embedded system applications |
Designed for general-purpose computing applications |
| Architecture |
Single-chip computer system with on-board memory, peripherals, and I/O interfaces |
CPU with minimal on-board memory, peripherals, and I/O interfaces
|
| Integration level |
Highly integrated |
Less integrated |
| System architecture |
Single-chip system |
CPU + support chips |
| Processing power |
Lower power |
Higher power |
| Instruction set |
Fixed instruction set |
More flexible |
| On-board memory |
On-chip memory |
No on-board memory |
| Input/Output (I/O) |
More I/O ports |
Fewer I/O ports |
| Peripheral devices |
On-board peripherals |
External peripherals |
| Cost |
Lower cost |
Higher cost |
| Power consumption |
Lower power |
Higher power |
| Applications |
Embedded systems |
General-purpose |
| Development |
Integrated development environment (IDE) provided by manufacturers, with specialized programming languages and tools |
Standard development tools and languages such as C, C++, and assembly
|
| Clock speed |
Lower clock speed, typically less than 100 MHz |
Higher clock speed, typically greater than 1 GHz
|