MICRO-PROCESSORS and MICRO -CONTROLLER topic
- 1. MICRO-PROCESSORS & MICRO-CONTROLLERS BY SHYAM AGARWAL PROJECT DEVELOPER FROM DATAPOINT
- 2. RISC & CISC RISC: RISC is a processor-based computing approach that offers the execution of computing tasks with multiple simple instructions. These were designed with the aim that computer processors perform simple instruction execution quite fastly. CISC: CISC is another processor-based computing approach that uses complex instruction sets or codes for the execution of any desired task. It puts the whole emphasis on the way to lessen the total instructions per program. Thus, it is associated with such processor hardware that can deal with the execution of various serially linked operations using a specific instruction.
- 3. A large number of instructions are present in the architecture. Very few instructions are present. The number of instructions is generally less than 100. Some instructions with long execution times. These include instructions that copy an entire block from one part of memory to another and others that copy multiple registers to and from memory. No instruction with a long execution time due to a very simple instruction set. Some early RISC machines did not even have an integer multiply instruction, requiring compilers to implement multiplication as a sequence of additions. CISC RISC CISC supports array. RISC does not support an array. Variable-length encodings of the instructions. Fixed-length encodings of the instructions are used.
- 4. Only single register set Multiple register sets are present Execution time is very high Execution time is very less It requires external memory for calculations It doesn’t require external memory for calculations Instructions can take several clock cycles With Harvard Architecture Single-cycle for each instruction Can be Harvard or Von-Neumann Architecture
- 5. Von Neumann and Harvard Architecture Von Neumann Architecture: Von Neumann Architecture is a digital computer architecture whose design is based on the concept of stored program computers where program data and instruction data are stored in the same memory. This architecture was designed by the famous mathematician and physicist John Von Neumann in 1945. Harvard Architecture: Harvard Architecture is the digital computer architecture whose design is based on the concept where there are separate storage and separate buses (signal path) for instruction and data. It was basically developed to overcome the bottleneck of Von Neumann Architecture.
- 6. VON NEUMANN ARCHITECTURE HARVARD ARCHITECTURE It is ancient computer architecture based on stored program computer concept. It is modern computer architecture based on Harvard Mark I relay based model. Same physical memory address is used for instructions and data. Separate physical memory address is used for instructions and data. There is common bus for data and instruction transfer. Separate buses are used for transferring data and instruction. Two clock cycles are required to execute single instruction. An instruction is executed in a single cycle. It is cheaper in cost. It is costly than Von Neumann Architecture.
- 7. CPU can not access instructions and read/write at the same time. CPU can access instructions and read/write at the same time. It is used in personal computers and small computers. It is used in micro controllers and signal processing.
- 8. Computer's Central Processing Unit (CPU) built on a single Integrated Circuit (IC) is called a microprocessor. A digital computer with one microprocessor which acts as a CPU is called microcomputer. The microprocessor contains millions of tiny components like transistors, registers, and diodes that work together. Microprocessor is a controlling unit of a micro-computer, fabricated on a small chip capable of performing ALU (Arithmetic Logical Unit) operations and communicating with the other devices connected to it. Microprocessor consists of an ALU, register array, and a control unit. ALU performs arithmetical and logical operations on the data received from the memory or an input device. MICRO-PROCESSORS
- 9. Block Diagram of Microprocessor The microprocessor follows a sequence: Fetch, Decode, and then Execute. Initially, the instructions are stored in the memory in a sequential order. The microprocessor fetches those instructions from the memory, then decodes it and executes those instructions till STOP instruction is reached. Later, it sends the result in binary to the output port. Between these processes, the register stores the temporarily data and ALU performs the computing functions.
- 10. • Instruction Set − It is the set of instructions that the microprocessor can understand. • Bandwidth − It is the number of bits processed in a single instruction. • Clock Speed − It determines the number of operations per second the processor can perform. It is expressed in megahertz (MHz) or gigahertz (GHz).It is also known as Clock Rate. • Word Length − It depends upon the width of internal data bus, registers, ALU, etc. An 8- bit microprocessor can process 8-bit data at a time. The word length ranges from 4 bits to 64 bits depending upon the type of the microcomputer. • Data Types − The microprocessor has multiple data type formats like binary, BCD, ASCII, signed and unsigned numbers. Important Keywords in Microprocessor
- 11. MICRO-CONTROLLERS A microcomputer made on a single semiconductor chip is called single-chip microcomputer. Since, single chip microcomputers are generally used in control applications, they are also called microcontrollers. A microcontroller is a small and low-cost microcomputer, which is designed to perform the specific tasks of embedded systems like displaying microwave’s information, receiving remote signals, etc. The general microcontroller consists of the processor, the memory (RAM, ROM, EPROM), Serial ports, peripherals (timers, counters), etc. Some single chip microcontrollers contain devices to perform specific functions such as DMA channels, A/D converter, serial port, pulse width modulation, etc.
- 12. MICROCONTROLLER MICROPROCESSOR Microcontrollers are used to execute a single task within an application. Microprocessors are used for big applications. Its designing and hardware cost is low. Its designing and hardware cost is high. Easy to replace. Not so easy to replace. It is built with CMOS technology, which requires less power to operate. Its power consumption is high because it has to control the entire system. It consists of CPU, RAM, ROM, I/O ports. It doesn’t consist of RAM, ROM, I/O ports. It uses its pins to interface to peripheral devices.
- 13. 8085 Microprocessor It is an 8-bit microprocessor designed by Intel in 1977 using NMOS technology. It is a 40 pin I.C. package fabricated on a single LSI chip. The Intel 8085 uses a single +5Vd.c. supply for its operation. 8-bit data bus 16-bit address bus, which can address upto 64KB A 16-bit program counter A 16-bit stack pointer Six 8-bit registers arranged in pairs: BC, DE, HL Requires +5V supply to operate at 3.2 MHZ single phase clock Ex: washing machines, microwave ovens, mobile phones, etc.
- 14. Pin diagram of Intel 8085 microprocessor
- 15. Address Bus and Data Bus: • A15-A8, it carries the most significant 8-bits of memory/IO address. • AD7-AD0, it carries the least significant 8-bit address and data bus. Control and Status Signals: • RD − This signal indicates that the selected IO or memory device is to be read and is ready for accepting data available on the data bus. • WR − This signal indicates that the data on the data bus is to be written into a selected memory or IO location. • ALE − It is a positive going pulse generated when a new operation is started by the microprocessor. When the pulse goes high, it indicates address. When the pulse goes down it indicates data. • IO/M − This signal is used to differentiate between IO and Memory operations, i.e. when it is high indicates IO operation and when it is low then it indicates memory operation. • S1 & S0 − These signals are used to identify the type of current operation.
- 16. Interrupts and Externally Initiated Signals: • HOLD (INPUT): HOLD indicates that another device is requesting for the use of the address and data bus. • HLDA (OUTPUT): HLDA is a signal for HOLD acknowledgement which indicates that the HOLD request has been received. After the removal of this request the HLDA goes low. • INTR (Input): INTR is an Interrupt Request Signal. Among interrupts it has the lowest priority. The INTR is enabled or disabled by software. • INTA (Output): INTA is an interrupt acknowledgement sent by the microprocessor after INTR is received. • RST 5.5, 6.5, 7.5 and TRAP (Inputs): These all are interrupts. When any interrupt is recognized the next instruction is executed from a fixed location in the memory • RESET IN − This signal is used to reset the microprocessor by setting the program counter to zero. • RESET OUT − This signal is used to reset all the connected devices when the microprocessor is reset.
- 17. 8051 microcontroller • 8051 microcontroller is designed by Intel in 1981. • It is an 8-bit microcontroller. • It is built with 40 pins DIP (dual inline package), 4kb of ROM storage and 128 bytes of RAM storage, 2 16-bit timers. • It consists of are four parallel 8-bit ports, which are programmable as well as addressable as per the requirement. • An on-chip crystal oscillator is integrated in the microcontroller having crystal frequency of 12 MHz. • The system bus consists of an 8-bit data bus, a 16-bit address bus and bus control signals.
- 19. • Pins 1 to 8 − These pins are known as Port 1. This port doesn’t serve any other functions. It is internally pulled up, bi-directional I/O port. • Pin 9 − It is a RESET pin, which is used to reset the microcontroller to its initial values. • Pins 10 to 17 − These pins are known as Port 3. This port serves some functions like interrupts, timer input, control signals, serial communication signals RxD and TxD, etc. • Pins 18 & 19 − These pins are used for interfacing an external crystal to get the system clock. • Pin 20 − This pin provides the power supply to the circuit. • Pins 21 to 28 − These pins are known as Port 2. It serves as I/O port. Higher order address bus signals are also multiplexed using this port.
- 20. • Pin 29 − This is PSEN pin which stands for Program Store Enable. It is used to read a signal from the external program memory. • Pin 30 − This is EA pin which stands for External Access input. It is used to enable/disable the external memory interfacing. • Pin 31 − This is ALE pin which stands for Address Latch Enable. It is used to demultiplex the address-data signal of port. • Pins 32 to 39 − These pins are known as Port 0. It serves as I/O port. Lower order address and data bus signals are multiplexed using this port. • Pin 40 − This pin is used to provide power supply to the circuit.