MICROCONTROLLER
A microcontroller is a system on a chip (SOC) it has CPU, I/O ports, timers, RAM, ROM on a single chip or it is like integrated on a single chip. Microcontrollers are designed for embedded applications it is used in automatically controlled devices such as automobile engines and control system by this microcontroller we could see changes in many devices especially electronic devices because of the integrated circuits quality is improved and smaller devices could be made with less cost thus microcontroller played a great role in our technology improvement. A microcontroller is a device that executes a program to control other devices or machines. Microcontrollers are programmed in higher level languages such as C++, or JAVA. A microcontroller is a single chip microcomputer which is made through VLSI fabrication it is also called an embedded controller because microcontroller and its support circuits are embedded or built into the devices they control.
A MICROCONTROLLER BASICALLY HAS THESE COMPONENTS
CPU- central processing unit
RAM- Random access memory ROM – Read only memory Input-output ports
Timers and counters
Interrupt control
Analog to digital converter
Digital to analog converter
Interrupt controls
Oscillatory circuit
8051 MICROCONTROLLER ARCHITECTURE
DIFFERENCE BETWEEN MICROCONTROLLER AND MICROPROCESSOR
Microprocessor and microcontroller are used for real-time applications they have some common features and have many differences. A microprocessor is an integrated circuit which has the only CPU they don’t have ROM RAM or I/O pins in them a designer has to add them externally to do the functions. But in case of microcontroller it has CPU ROM, RAM, and others within a chip it is also known as a minicomputer. The microcontroller does specific task-specific means were input and output relation is defined some examples are keyboard mouse telephone, mobile watches… were as in microprocessor it doesn’t do any specific task were input-output relation is not defined such as developing software, websites…
CLASSIFICATION OF MICROCONTROLLER
Microcontrollers are divided by their bits, memory architecture, memory device and instruction set
CLASSIFICATION ACCORDING TO BITS
8 bit- In this if the internal bus is 8 bit then the ALU performs arithmetic and logic operations. Examples are 8051/8031/ pic1x.
16 bit- this microcontroller performance is greater compared to 8-bit. 16 bit can use 16 bit for its operations were as in 8-bit it is only 8-bit examples are 8051 extended, pic2x
32-bit - it uses 32 bit to perform its operations these are used in medical devices and in control systems PIC3X is an example
CLASSIFICATION ACCORDING TO MEMORY DEVICES
Embedded memory microcontroller – This is a type of microcontroller in which all the functional blocks are available in a chip data memory I/O ports
External memory microcontroller – in this microcontroller all functional blocks are not available 8031 doesn’t have any program memory
CLASSIFICATION ACCORDING TO INSTRUCTION SET
CISC – complex instruction set computer it allows the user to use one instruction to do the functions of many simple instructions
RISC- reduced instruction set computer in this instruction set is reduced each instruction can be operated on any register or in any addressing mode
CLASSIFICATION ACCORDING TO MEMORY ARCHITECTURE
Harvard memory architecture- in this microcontroller the program and data memory doesn’t have a similar memory address space
Princeton memory architecture- in this the program and data memory have similar address space
TYPES OF MICROCONTROLLER
8051 microcontroller
It is designed by Intel in 1981 and it is an 8 bit microcontroller it has 40 pins dual inline package 128 bytes of RAM 4k byte of ROM in 8051 there are 2 busses one for programming and other for data programming in microcontroller is complicated basically we write a program in C language and then it is converted to machine language understood by microcontroller two types of memory is present the program memory and data memory program memory stores the data being executed while data memory stores the result temporarily
Renesas microcontroller
It is in the automotive microcontroller family that offers high-performance features with low power consumption this microcontroller offers high security and embedded safety character for the automotive applications RX microcontroller is an example which has 32 bit
AVR microcontrollers
The AVR microcontrollers have modified Harvard RISC architecture with separate memories for data and program and speed of AVR is really high when compared to PIC and 8051
APPLICATIONS
- Industrial automation
- Communication application
- Motor control applications
- Test and measurement
- Medical applications
- Automobiles
- Cameras
- Security alarms
- Mobile phones