A microcontroller is an integrated circuit (IC) that is a compact, low-cost, self-contained computer that is used in embedded systems to perform a specific purpose. A microcontroller (also known as a microcontroller unit or MCU) is a small computer that is built into a single chip. It can alternatively be described as a clock-driven, register-based programmable silicon device that receives input and processes it according to instructions stored in memory.
A computer is a multipurpose device that may be used for word processing, watching movies, editing videos, accessing the web, and producing software, among other things. A microcontroller, on the other hand, is designed to perform specialized functions like controlling a washing machine or an air conditioner.
How does it work?
A microcontroller's CPU processes data sent to its input ports and outputs it via output pins. The asynchronous sequential logic circuit performs or drives it.
A sequential circuit, according to digital circuit theory, is a logical circuit whose output is dependent not only on current inputs but also on previous input history. In synchronous sequential circuits, the device's state changes only at discrete intervals determined by a clock signal. When compared to an asynchronous system, the fundamental advantage of a synchronous system is its simplicity.
I'm sure you're aware of the propagation lag. To process data, a microcontroller employs a large number of logic gates. Propagation delay is the time it takes for these gates to alter their output state based on their inputs.
To make the logic circuit robust and trustworthy, the interval between each clock pulse should be longer than the propagation delay. As a result, the maximum operating speed of a microcontroller is determined, which varies between microcontrollers.
As previously stated, a microcontroller contains many components such as a CPU, RAM, and ROM.
CPU
A CPU is similar to a computer processor, which comprises the Arithmetical and Logical Unit (ALU), Control Unit, and Register Array. ALU performs all arithmetic and logical operations on data received from input devices or memory, as the name implies. A register array is made up of a sequence of registers such as accumulator (A), B, C, D, and so on that operate as temporary fast access memory locations for data processing. The control unit, as its name implies, regulates the flow of instructions and data throughout the system.
RAM
RAM stands for Random Access Memory. Similar to a computer, RAM is used to store data dynamically while the microcontroller is executing instructions. It is a volatile memory, which means when the power goes off all data is gone.
ROM or Program Memory
ROM stands for Read-Only Memory. In old microcontrollers flash memory was one-time programmable which is why it is called ROM. But in the latest microcontrollers, it is re-programmable, ie. EEPROM (Electrically Erasable Programmable Read-Only Memory). ROM is used to store the program or instructions which need to be executed.
Microcontrollers have a number of general-purpose input-output (GPIO) pins that can be configured as an input or output pin by writing to certain configuration registers. This pin can read and write HIGH or LOW states from/to its pins, allowing it to communicate with the outside world.
Clock
As previously said, a microcontroller requires a clock to operate and is powered by sequential logic. An external clock source, such as a crystal oscillator, or an internal clock source, such as an RC oscillator, can be used. Clocking choices will vary depending on the microcontroller. Internal PLL (Phase Locked Loop) or FLL (Frequency Locked Loop) to multiply clock to higher frequencies is available on some advanced microcontrollers.
Peripherals
Microcontrollers will also have other peripherals as below.
- UART, SPI, and I2C for serial communication.
- Timers/Counters
- Capture/Compare/PWM modules
- Analogue to Digital Converter
Why do we need a Microcontroller?
A microcontroller's instruction set and capabilities can be used to program it to do a specific task. When we try to address a problem just using hardware, the solution can become extremely complicated.
If you wish to construct a large structure, BRICKS will make the procedure straightforward and cost-effective. It will also allow you to design the building in whatever shape or size you like. The bricks that you can utilize to fix your problem are the instructions stored in a microcontroller. You can quickly solve difficult programs by following those guidelines.
Applications
Simply take a break from reading and take a glance around your home. Everything in your kitchen, including the TV, TV remote, Set Top Box, Microwave Oven, Washing Machine, Air Conditioner, and even the car parked on your porch, uses a microcontroller.
Different Microcontrollers
Microcontrollers are manufactured by a variety of firms and are accessible on the market.
Microcontrollers 8051
The 8051 microcontroller series is a widely-used general-purpose microcontroller. Intel is the first company to produce it. Nowadays, we can observe a variety of 8051 clones with varied RAM, ROM, peripherals, and other features, created by firms like Atmel, Texas Instruments, Philips, Infineon, and others. Microcontrollers in the 8051 series are popular among enthusiasts and educators.
PIC Microcontrollers
Peripheral Interface Controller (PIC) is an acronym for Peripheral Interface Controller. Microchip Inc. produces this line of microcontrollers. Professionals, students, and electronics hobbyists all like it. It is inexpensive and widely available, and it is available in 8-bit, 16-bit, and 32-bit architectures.
Microcontrollers from ARM
ARM stands for Advanced RISC Machine, and it is a microcontroller with a reduced instruction set computer (RISC). The most common among professionals are ARM microcontrollers. ARM microcontrollers are made by firms such as NXP Semiconductors, STMicroelectronics, Microchip Inc., and Atmel, among others.
Microcontrollers AVR
Hobbyists and students are familiar with AVR microcontrollers. Atmel invented AVR microcontrollers, which were later acquired by Microchip. The AVR microcontroller is used in the popular Arduino boards.
Advantages
Miniature Size
A microcontroller, unlike a computer microprocessor, is designed to perform certain functions. As a result, hardware needs such as RAM, ROM, and other peripherals are minimal. As a result, everything is embedded into a single chip, resulting in a significant reduction in total size.
Low-cost
microcontrollers are less expensive than microprocessors because they have fewer RAM, ROM, and peripherals contained in a single chip.
Power Consumption is Reduced
Because a microcontroller employs a smaller collection of hardware, such as RAM, ROM, and other peripherals, it consumes extremely little power.
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Microcontroller