MICROOCESSORS AND MICROCONTROLLER: Computer: Computer is a multiprogram device that reads binary instructions from memory, accepts binary data as input, processes data according to instruction given and provides result as output. Instructions: These are the commands given to the computer to perform specified task. Program: Set of instructions given to the computer to perform specified task is called program .

CPU- Central processing unit: Hardware: Physical components present inside a computer is called Hardware. CPU- Central processing unit: This is the unit within computer which performs arithmetic and logical computations and all control functions. ALU- Arithmetic and logical unit: This unit performs all arithmetic and logical operations. Control unit: This unit produces various control signals required in the computer.

Microcontrollers & Embedded Processors Microprocessors, such as Intel Pentium and Motorola 68000 contain no appreciable RAM or ROM and are referred to as general purpose microprocessors. External devices must be connected to make them functional and useful. Microcontrollers contain in-chip RAM, ROM and other peripherals making them ideal for small, inexpensive applications.

Microprocessor: Bit length: This is powerful IC chip which contains whole CPU with ALU and timing unit. Bit length: This is the number of bits that microprocessor can manipulate at a time. Different microprocessors are , Intel 4004-4 bit microprocessor Intel 8085-8 bit microprocessor Intel 8086,80186,80286 etc -16 bit microprocessor Intel 80386,80486,80586(Pentium)-32 bit microprocessor

Microcomputer: Microcontroller: A microprocessor connected to memory and I/O devices is called microcomputer. Microcontroller: This is single chip microcomputer which contains microprocessor,memory and I/O ports within one chip. A microcontroller contains microprocessor and one or more of the following components. Memory. I/O ports Analog and Digital converter Digital to Analog converter Timers and counters

Microcontroller applications: In home appliances such as Refrigerators,washing machines, microwave ovens etc. Automobile engines Industrial applications. Biomedical instruments Miltary applications Traffic controlling etc.

Difference between microprocessors and microcontrollers: Has ALU and timing unit Has ALU,timing unit, memory I/O port, timers,counters etc. Normally pins are unifunctional Most of the pins are multifunctional Few bit related instructions Many bit related instructions Microprocessor based design requires more hardware Microcontroller based design requires less hardware

RISC and CISC machines: RISC means reduced instruction set computers . Example PIC 16F87X CISC means complex instruction set computers. Example Intel 8051 Comparison of RISC and CISC RISC CISC 1. Instructions take one or two cycles. 1. Instructions take multiple cycles. 2.Only load /store instructions are used to access memory 2. In addition to load/store memory access is possible with other instructions also. 3.Instructions executed by hardware 3. Instructions executed by microprogram. 4.Fixed format instructions 4.Variable format instructions 5.Few addressing modes 5. Many addressing modes 6.Few instructions 6.Complex instruction set 7.Multiple register bank 7.Single register bank

Von neuman and Harvard architecture: Von neuman architecture Harvard architecture Single address and data bus is used to connect program memory(ROM)& data memory(RAM) Separate buses are used for connecting program memory(ROM)& data memory(RAM) Accessing from data memory and program memory can not be done in parallel Accessing from data memory and program memory can be done in parallel Speed of execution is slow Speed of execution is fast

Programming languages: 1 Programming languages: 1.machine language: In this language binary codes are used to write program. 2. Assembly language : In this mnemonics are used for writing programs. 3. High level language: In this statements are used to write programs. Assembler: This is a software which converts assembly language program, to machine code. Compiler: This is a software which converts high level language program to machine code.