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What is a Microcontroller?
Microcontrollers
Source: Wikimedia Commons
Before defining the microcontroller, it’s vital to note that it differs from the microprocessor (which we’ll discuss later in the article).
That said, the microcontroller is a very large-scale integration IC. It comprises the I/O ports, logic unit, memory, electronic computing unit, and other modules fused on a single chip. You can also refer to the device as a Single-Chip-Computer.
Additionally, the microcontroller is also an Embedded Controller. And it’s because the device, alongside the supporting circuitry, goes into the appliance it controls.
You can find microcontrollers in many devices or applications that display data, measure, control, store, or calculate. Interestingly, the Automobile Industry tops the list of the biggest microcontroller users. After all, vehicles need the device for engine control and regulating other systems.
Another area where microcontrollers are common is in consumer electronics. So, you can find microcontrollers in ovens, digital cameras, DVD players, etc. Test and measuring equipment also use microcontrollers, e.g., function generators, multimeters, etc.
How Does the Microcontroller Work?
Typically, microcontrollers run a particular program and stick to one task. So, they work by getting input from the device that they control. Consequently, this helps the microcontrollers maintain control. It does this by sending signals to different parts of the device.
For instance, a TV’s microcontroller works by getting input from the remote control. Then, it delivers the output on the TV screen.
The Types of microcontrollers
We have different microcontrollers based on the following categories: instruction sets, memory, and bits.
Instruction Sets
There are two categories of microcontrollers based on the instruction set configuration:
RISC
This acronym means Reduced Instruction Set Computers. It does this by reducing the clock cycle for every instruction. And it helps to lessen the working time.
CISC
This acronym represents Complex Instruction Set Computer. It permits users to fix one instruction as an option for different simple commands.
Memory
Memory Card (RAM)
Source: Wikimedia Commons
In the memory configuration category, there are two types of microcontrollers:
Embedded Memory Microcontroller
This type of microcontroller usually has so many components on the chip like timers and counters, I/O ports, data memory, interrupts, etc. An example of an embedded memory microcontroller is the Intel 8051.
External Memory Microcontroller
The design of this type of microcontroller doesn’t have a program memory on its chip. An excellent example of an external memory microcontroller is the Intel 8031.
Bits
There are three types of microcontrollers in the bit configuration category:
32-Bit Microcontroller
You can find the 32-bit microcontroller in appliances that use automatic control like medical appliances, etc.
16-Bit Microcontroller
The 16-bit microcontroller is useful for high-performance and accuracy applications. So, you can use this microcontroller to do logical and arithmetic operations. An excellent example of this microcontroller is the Intel 8096.
8-Bit Microcontroller
The 8-bit microcontroller is the least in this category. And you can use it to carry out simple tasks like executing logical and arithmetic operations like division, subtraction, etc. Also, examples of this microcontroller are Intel 8051 and 8031.
Basic Structure of a Microcontroller
The microcontroller has three fundamental components: I/O ports, memory, and the Central Processing Unit.
Other components of this device are vital as well. But the ones mentioned above are supporting devices. So, we’ll take a close look at the primary components of a microcontroller based on its structure.
Memory
Typically, most computational systems need two types of memory: Data and Program memory. The data memory helps to keep temporary information while it carries out instructions. But the Program memory consists of the program. That is, it contains the instructions that the CPU will perform.
Bus
The System Bus is one of the least talked about components. But it’s a vital part of the microcontroller.
It refers to a collection of connecting wires that link the CPU to other peripherals like the I/O ports and other supporting components.
CPU
The CPU is like the microcontroller’s rain. And it has two parts: the CU (Control Unit) and ALU (Arithmetic Logic Unit).
So, the CPU is responsible for decoding, reading, and performing instructions to execute Data, Logic, and Arithmetic transfer operations.
Interrupts
The interrupts are another vital component of the microcontroller. And it has an Interrupt Handling Mechanism. Also, this component can be software-related, eternal, hardware-related, or internal.
I/O Ports
The I/O refers to the Input/Output ports. This component offers the microcontroller an interface to external connections. For instance, Input devices like keypads, switches, etc., give information from a user to the CPU. And it does this in a Binary Data form.
So, when the CPU gets the information from the input devices, it performs suitable instructions. Then, it responds via the output devices like printers, displays, LEDs, etc.
Serial Port
This component helps the microcontroller interact via serial communication. A microcontroller can only communicate with other external peripherals and devices via the serial port. The UART is the microcontroller’s most common serial communication.
DAC
This acronym stands for Digital to Analog Converter. It’s a circuit that changes Digital signals to Analog signals. Also, this component connects the microcontroller’s CPU and analog devices (external).
ADC
The ADC acronym stands for Analog to Digital converter. And it’s the opposite of the DAC. That is, the circuit helps to change Analog signals to Digital signals. Also, this circuit creates a connection between the external Analog Input devices and the microcontroller’s CPU.
Further, it’s crucial to note that analog devices are mostly sensors. Hence, for the CPU to understand the communication, the analog data must change to digital.
Counters/Timers
The counters and timers are vital components of the microcontroller. They are responsible for offering operations of counting external events and time delays. Also, the components offer Clock Control, Function Generation, etc.
Configuration Bits
Microcontrollers usually have a unique bit. And it’s the Configuration bits. This component helps to structure the microcontroller’s special options, which include (but aren’t restricted to):
- Low Voltage Programming On/Off
- Power Up Timer On/Off
- Internal/External switchover On/Off
- Oscillator Type
- Fail-Safe Clock Monitor On/Off
- Brown Out Reset On/Off
- Watchdog Timer On/Off
Also, on a PIC microcontroller, you’ll notice configuration bits. It’s responsible for data code protection and program code protection.
That is, the configuration bits stop external programming hardware from reading your program and data spaces. Hence, it will be difficult for others to steal your code.
Comparison Between the Microprocessor and Microcontroller
Microprocessor
Source: Wikimedia Commons
Microcontroller
Source: Wikimedia Commons
The microcontroller is a computer that consists of timers, ROM, and other peripherals. Hence, you can call them mini-computers. Plus, they come in a different version. However, the microprocessors are integrated circuits. And they have processing power with only a CPU inside them.
Here’s a table showing their differences:
Pros
- Since it writes and stores instructions in the memory, the microcontroller doesn’t need complex operating systems.
- The chip doesn’t require external interfacing of primary components like the I/O ports.
- You can program the I/O ports.
- Putting all the vital components reduces the area of the product, cost, and design time.
Cons
- It doesn’t have an operating system. Hence, you have to write all the commands.
- The microcontroller’s memory (depending on the amount) can limit the instruction that the device can perform.
Wrapping Up
In summary, the microcontroller basics explain the power of the single-chip microcomputer. Further, it comprises several peripherals that make up the device’s structure like the memory, CPU, I/O ports, Oscillatory circuits, etc. Also, manufacturers build the microcontroller into devices they control.
Each of the peripherals plays a vital role that contributes to the function of the microcontroller. What do you think about microcontrollers? Do you need help with getting the best one for your project? Please feel free to reach us.
