INTRODUCTION TO MICROPROCESSORS Compiled by: Seble N. What is Microprocessor? 2 Intel coined the term in 1971 usually made of millions of microscopic array of electronic circuits and electronic components (resistors, capacitors, inductors…) are diffused or implanted to surface of small silicon chip its basic function is to take input, process it and then provide appropriate output Examples Pentium, AMD , a PowerPC, a Sun-SPARC or any of the many other brands and types of microprocessors Function of microprocessors 3 A microprocessor performs three basic steps: First, it fetches an instruction from memory, Second, it uses decoding circuitry to determine what the instruction means (i.e., identify the operations and the devices involved in it) and Third, it executes the instruction Components of microprocessor 4 ALU (Arithmetic/Logic Unit) performs all arithmetic and logic operations Control Unit holds the circuitry that controls the process of executing, decoding and fetching program instructions it controls the flow of data between the μ-processor and memory & peripherals it controls the operation of ALU, I/O devices, and memory unit Registers A register is a very small & very fast memory that is built into the CPU in order to store the current data and instructions which are being executed by the CPU Modes of Processing 5 Real Mode One program at a time Protected Mode Can run more than one program concurrently and protect them from each other Virtual Mode The processor can swap portion of the memory to the hard disk; in this way programs running concurrently will have more space to operate Characteristics of microprocessors 6 Instruction set the set of instructions that a microprocessor can understand or execute Word length refers to the number of bits a processor can process at a time Eg. a 4-bit processor means the ALU can perform a 4-bit data operation at a time the longer the word length is the more powerful the processor is and can process data at a faster speed as compared to processor with shorter word length Characteristics of microprocessors 7 Speed measured in HZ = 1cycle/second Some processors may complete a single instruction per cycle, or may take one or more cycles a 2 GHZ CPU may compute 2 billion instructions per second, if it is able to complete a single instruction in a single cycle but if it takes 2 cycles to complete a single instruction then it is only able to compute 1 billion instructions per second Cache Size The size of the cache memory Characteristics of microprocessors … 8 Size of registers refers to the number of bits a microprocessor’s register can hold at a time the size of addressable memory is often determined by the width of registers Data bus width Refers to the number of bits a data bus can carry at a time Classes of microprocessors 9 Complex instruction set computer (CISC) Reduced instruction set computer (RISC) Application Specific Integrated Circuit (ASIC) Digital Signal Multiprocessors (DSP) Superscalar Microprocessors Classes of microprocessors … 10 Complex instruction set computer (CISC) is more complex and has the ability to perform complex commands it allows the user to apply 1 instruction as an alternative to many simple instructions can perform complex functions with one instruction Ex: Intel’s Pentium and Atom chips Classes of microprocessors … 11 Reduced instruction set computer (RISC) are made according to the function in which the microprocessor can carry out small things in specific command In this way these processors completes more commands at a faster rate is simpler, smaller and faster usually need multiple instructions Ex: PowerPC and ARM's Cortex chips Evolution of Microprocessors 12 Computing technologies based on vacuum tubes and transistors In 1959, Fair child semiconductors invented the first integrated circuit In 1968, Gordan Moore, Robert Noyce & Andrew Grove founded Intel(Integrated Electronics) In 1971, the first microprocessor, Intel 4004 was released In 1972, Intel released the first 8-bit microprocessor Intel 8008 In 1976, MOS technologies introduced the Motorola 6502 an 8-bit processor, used in Apple I and II In 1981, the first PC was created by IBM using intel’s 8088 microprocessor Several companies like Intel, AMD, IBM, ARM, PowerPC, Motorola… make general purpose processors that are designed for personal computers, laptops, mobile devices and large central servers Evolution of microprocessors 13 Intel is generally regarded as the company that sets the benchmark for others to follow From the earlier Pentium and Centrino microprocessors to the Core 2, Core i series Atom chips for mobiles The high-end Itanium and Xeon processors for server applications Over 90% of laptops use Intel microprocessors HP, Dell, Apple, Samsung, Sony, Toshiba … Top CPU manufacturers 14 Intel AMD Qualcomm Mediatek NVIDIA IBM Samsung Motorola Hewlett-Packard (hp) Dell Acer … Intel microprocessors 15 Intel 4004 Intel 8080 Intel 8085 Intel 8088 Intel 8086 Intel 80286 Intel 80386 Intel 80486 Pentium Pentium II and III Dual Core/ Core Core i3, i5, i7 Intel microprocessors … 4-bits processors 16 Intel 4004 1971- the first commercially available processor as well as the first complete CPU on a single chip a 4-bit processor: able to operate on 4 bits of data at a time 4-bit data bus had 2,300 transistors clock speed of 108KHZ 640 bytes addressable memory was designed for use in calculator but also used In traffic light controller, Blood analyzers, and even in the NASA pioneer 10 deep space probe Intel microprocessors … 8-bits processors 17 Intel 8008 first 8-bit microprocessor 200KHz clock speed and 3,500 transistors, had 6 , 8-bit registers 8-bit data bus can address up to 16KB Intel 8080 1974 with 4,500 transistors with up to 2-3MHz can address up to 64KB became famous for being used in the Altair 8800 as well as in Boeing's AGM- 86 cruise missile Intel 8085 was popular as an embedded controller ran at 5MHZ and contained 6500 transistors Intel microprocessors … 16-bits processors 18 Intel 8086 1978, first x86 family microprocessor 16-bit: all registers, internal and external buses Used 20-bit addressing Can address 1 million bytes of internal memory 29,000 transistors, 5MHz initially Intel 8088 was identical to the 8086 with the exception of its 8-bit internal bus The IBM 5150, the first IBM PC, came with the 8088 Intel microprocessors … 16-bits processors 19 Intel 80286 can operate on real and protected mode 134,000 transistors, 6M-8MHz initially runs faster than the preceding processors can address up to 16 million bytes of internal memory was popular in IBM-PC AT and AT PC clones Intel microprocessors … 32-bits processors 20 Intel 80386 the first 32-bit microprocessor 32 bit registers & data bus can operate on protected mode and supports virtual mode 275,000 transistors 12MHz initially, later 33MHz Andy Grove decided to single-source producing 386 to AMD Later changed in 1991 by AMD AM386 Intel microprocessors … 32-bits processors 22 Pentium (Pentium I) 32 bit registers 64 bit data bus Has a high speed cache memory It can execute more than one instruction per clock cycle Pentium II and III Have a dual independent bus that provides separate path to the system cache and memory On-die L2 cache Intel microprocessors … 64-bits processors 23 New instruction set, not at all related to x86. Itanium Released May 29, 2001 733 MHz to 800 MHz 2MB cache Itanium 2 Released July 2002 900 MHz – 1.6 GHz Intel microprocessors … 64-bits processors 24 Intel core 2 x86-64 microprocessor Two cores on one die Number of transistors: 291 million 64 KB of L1 cache per core 1.86-3.00 GHz Intel core i series Intel core i3, i5, i7 Intel microprocessors … 25 What is an x86 architecture? 26 x86 is a family of backward compatible instruction set architectures based on the Intel 8086 CPU and its Intel 8088 variant the term "x86" came into being because the names of several successors to Intel's 8086 processor end in "86", including the 80186, 80286, 80386 and 80486 processors all newer processors using Intel's x86 instruction set are still referred to as x86, i386, or i686 compatible (which means they all use extensions of the original 8086 instruction set) Intel 8086 27 1978, first x86 family microprocessor 16-bit: all registers, internal and external buses a CISC processor can address 1 million bytes of internal memory used 20-bit addressing to date backward compatibility has been maintained 8086 Microprocessor Architecture 28 The Basic Architecture of the Intel 8086 The processor is partitioned into two logical units Execution Unit (EU) Bus Interface Unit(BIU) Why partition is needed? Because the processor runs considerably faster than memory Architecture of 8086 29 Execution Unit 30 takes care of the processing including arithmetic and logic operations its role is to execute instructions Contains ALU, Control Unit and Registers Bus Interface Unit (BIU) 31 Its role is to deliver instructions and data to the EU Function to manage the bus control unit, segment registers and instruction queue to provide access to instructions from memory and place them in an instruction queue, which varies in size depending on the processor This feature enables the BIU to look ahead and prefetch instructions so that there is always a queue of instructions ready to execute Internal Memory of 8086 32 Memory consists of cells organized in 8-bit