Microprocessor Or Microcontroller?

9/27/14MicroprocessororMicrocontroller?A little Historyn What is a computer? [Merriam-WebsterDictionary] one thatcomputes; specifically : programmableelectronic device that can store, retrieve, andprocess data. [Wikipedia] A computer is a machine thatmanipulates data according to a list ofinstructions.n Classification of Computers (power and price) Personal computersMainframesSupercomputersDedicated controllers – Embedded controllers1

9/27/14MainframesIBM 9000Massive amounts of memoryn Use large data words 64 bits or greatern Mostly used for military defense and largebusiness data processingn Examples: IBM 4381, Honeywell DPS8n Personal Computersn Any general-purpose computer intended to be operated directly by an end usern Range from small microcomputers that work with 4-bitwords to PCs working with 32-bit words or moreThey contain a Processor - called different namesn Microprocessor– built using Very-Large-ScaleIntegration technology; the entire circuit is on asingle chip Central Processing Unit (CPU) Microprocessor Unit (MPU) – similar to CPUhttp://en.wikipedia.org/wiki/Personal computer2

9/27/14Supercomputersn Fastest and most powerful mainframes Contain multiple central processors (CPU)Used for scientific applications, and number crunchingNow have petaflops performancen n n FLoating Point Operations Per Second (FLOPS)Used to measure the speed f the computerExamples of special-purpose supercomputers: Belle, Deep Blue, and Hydra, for playing chessReconfigurable computing machines or parts of machinesGRAPE, for astrophysics and molecular dynamicsDeep Crack, for breaking the DES cipherMDGRAPE-3, for protein structure terMicrocontrollers –Embedded Systemsn n An embedded system is a special-purpose computersystem designed to perform one or a few dedicatedfunctions often with real-timeAn integrated device which consists of multiple devices n Microprocessor (MPU)MemoryI/O (Input/Output) portsOften has its own dedicated software3

9/27/14A little aboutMicroprocessor-basedSystems Evolutionn n First came transistorsIntegrated circuits n 1- Microprocessors (MPU) n SSI (Small-Scale Integration) to ULSIVery Large Scale Integration circuits (VLSI)Microcomputers (with CPU being a microprocessor)Components: Memory, CPU, Peripherals (I/O)Example: Personal computers2- Microcontroller (MCU) Microcomputers (with CPU being a microprocessor)Many special function peripheral are integrated on a singlecircuitTypes: General Purpose or Embedded System (with specialfunctionalities)4

9/27/14Microprocessor-Based Systems Central Processing Unit (CPU) Memory Input/Output (I/O) circuitry Buses– Address bus– Data bus– Control aysMicroprocessor-based SystemControl Unit5

9/27/14Microprocessor-Based System withBuses: Address, Data, and ControlMicroprocessor-based SystemsMicroprocessorn Themicroprocessor (MPU) is a computing andlogic device that executes binary instructions in asequence stored in memory.n Characteristics: Generalpurpose central processor unit (CPU) Binary Register-based Clock-driven Programmable6

9/27/14Evolution of CPUsTransistorsn n n n Vacuum Tubes: A devise to control,modify, and amplify electric signalsThen can transistors Designed by John Bardeen, WilliamShockley, and Walter Brattain,scientists at the Bell TelephoneLaboratories in Murray Hill, NewJersey - 1947In 1960 Jack Kilby and Robert Noycedesigned the first integrated circuit (IC)Fairchild company manufactured logicgates7

9/27/14Integrated Circuitsn n n Advances inmanufacturing allowedpacking more transistorson a single chipTransistors andIntegrated Circuits fromSSI (Small-ScaleIntegration) to ULSIBirth of a microprocessorand its revolutionaryimpactMicroprocessorsn n n n Noyce and Gordon Moorestarted IntelIntel designed he firstcalculatorIntel designed the firstprogrammable calculatorIntel designed the firstmicroprocessor in 1971 Model 4004 4-bit; 2300 transistors,640 bytes of memory,108 KHz clock speed8

9/27/14First Processorsn n n n n Intel released the 8086, a 16-bit microprocessor,in 1978Motorola followed with the MC68000 as their 16bit processor The 16-bit processor works with 16 bit words,rather than 8 bit words Instructions are executed faster Provide single instructions for more complexinstructions such as multiply and divide16 bit processors evolved into 32 bit processorsIntel released the 80386Motorola released the MC68020Evolution of CPUsIn 1965, Gordon Moore, co-founder of Intel, indicated that the number of transistors per square inch on integratedcircuits had doubled every year since the integrated circuit was invented. Moore predicted that this trend wouldcontinue for the foreseeable future.9

9/27/14Evolution of CPUsn Intel Core i7 Intel Core i7-5960X Processor ExtremeEdition (20M Cache, up to 3.50 GHz) 8 Cores, 16 Threads 64 bit Instruction licon/2billion.htmMicroprocessor-based SystemsMemory Types R/W:Read/Write Memory; also called RAMIt is volatile (losses information as power isremoved)n Write means the processor can store informationn Read means the processor can receive informationfrom the memoryn Acts like a Blackboard!ROM: Read-Only memory;n It is typically non-volatile (permanent) – can beerasablen It is similar to a Page from your textbookn 10

9/27/14Microprocessor-based SystemsMemory ClassificationBasic Technologies:SemiconductorMagneticOptical(or combination)ExpensiveFast/CheapSlowOnetime programmableElectronically ErasablePROMMicroprocessor-basedSystems-one transistor and onecapacitor to store a bitMemory Classification-Leakage problem, thusrequires refreshing-Used for dynamic data/program storage-Cheap and slow!-4/6 transistor tosave a single bit- Volatile- Fast butexpensiveExpensiveFast/CheapSlowOnetime programmableElectronically ErasablePROM11

9/27/14Erasable ROMsn Masked Programmed ROMn Programmable ROM (PROM)n Erasable Programmable ROM (EPROM) n Can be programmed in the field via the programmerUses ultraviolet light to erase (through a quartz window)OTP refers to one-time programmableElectrically Erasable Programmable ROM (EEPROM) n Programmed by the manufacturerEach program location can be individually erasedExpensiveRequires programmerFLASH Can be programmed in-circuit (in-system)Easy to erase (no programmer)Only one section can be erased/written at a time (typically 64 bytes at a time)Microprocessor-based SystemsI/O Portsn n The way the computer communicates with theoutside world devicesI/O ports are connected to Peripherals Peripherals are I/O devicesn n Input devicesOutput devicesExamplesn n n n Printers and modems,keyboard and mousescannerUniversal Serial Bus (USB)12

9/27/14Microprocessor-basedSystems - BUSn The three components – MPU, memory, and I/O – are connected by agroup of wires called the BUSn Address busn n n Control bus n consists of 16, 20, 24, or 32 parallel signal lines (wires) - unidirectionalthese lines contain the address of the memory location to read or writtenconsists of 4 to 10 (or more) parallel signal linesCPU sends signals along these lines to memory and to I/O portsn examples: Memory Read, Memory Write, I/O Read, I/O WriteData bus consists of 8,16, or 32 parallel signal linesbi-directionalonly one device at a time can have its outputs enabled,this requires the devices to have three-state outputExpanded Microprocessor-Based System1. Note the directionsof busses2. What is the width ofthe address bus?3. What is the value ofthe Address but toaccess the firstregister of the R/WM?Remember: 111 1111 1111 2 11 2K13

9/27/14So what aremicrocontrollers?First Microcontrollersn n n n IBM started using Intel processors in its PC Intel started its 8042 and 8048 (8-bitmicrocontroller) – using in printersApple Macintosh used Motorola 680001980 Intel abandoned microcontroller businessBy 1989 Microchip was a major player indesigning microcontrollers PIC: Peripheral Interface Controller14

9/27/14Embedded controllersSoftware Characteristicsn n n No operating systemsExecute a single program, tailored exactly to thecontroller hardwareAssembly language (vs. High-level language) Not transportable, machine specific Programmer need to know CPU architecture Speed Program size UniquenessMicrocontroller Unit (MCU)Block Diagramn An integrated electronic computing and logic device thatincludes three major components on a single chip n Includes support devices n MicroprocessorMemoryI/O portsTimersA/D converterSerial I/OParallel Slave PortAll components connected by common communicationlines called the system bus.15

9/27/14MCU Architecturen n RISC (Harvard) Reduced instruction set computer Simple operations Simple addressing modes Longer compiled program bust faster toexecute Uses pipeliningCISC (Von Neuman) Complex instruction set computer More complex instructions (closer to highlevel language support)Bench marks: How to compare MCUs togetherMIPS: Million Instructions / second (Useful when the compilers are the same)Main 8-bit Controllersn Microchip-- PIC Microcontrollers n Motorola– now Freescale n CISC architectureHas hundreds of instructionsExamples: 68HC05, 68HC08, 68HC11Intel– now Marvell n RISC architecture (reduced instruction set computer)Has sold over 2 billion as of 2002Cost effective and rich in peripheralsCISC architectureHas hundreds of instructionsExamples: 8051, 8052Many difference manufacturers: Philips, Dallas/MAXIM Semiconductor,etc.Atmel RISC architecture (reduced instruction set computer) –Cost effective and rich in peripheralsAVR16

9/27/14High-level LanguageAssembly LanguageSoftware: From Machineto High-Level Languages (1 of 3)n Machine LanguageMachine Language: binary instructions Allprograms are converted into the machinelanguage of a processor for execution Difficultto decipher and write Prone to cause many errors in writingHigh-level LanguageSoftware: From Machineto High-Level Languages (2 of 3)n Assembly LanguageMachine LanguageAssembly Language: machine instructionsrepresented in mnemonics Hasone-to-one correspondence with machineinstructions Efficient in execution and use of memory;machine-specific and not easy to troubleshoot17

9/27/14High-level LanguageSoftware: From Machineto High-Level Languages (3 of 3)n Assembly LanguageMachine LanguageHigh-Level Languages (such as BASIC, C,and C ) Writtenin statements of spoken languages(such as English)machine independentn easy to write and troubleshootn requires large memory and less efficient inexecutionn UnsignedData Format (8-bit) (1 of 4)n SignedUnsigned Integers: All eight bits (Bit0 toBit7) represent the magnitude of a number Range0 to FF in Hex and 0 to 255 in decimal18

9/27/14UnsignedData Format (8-bit) (2 of 4)n SignedSigned Integers: Seven bits (Bit0 to Bit6)represent the magnitude of a number. Theeighth bit (Bit7) represents the sign ofa number. The number is positive whenBit7 is zero and negative when Bit7 is one. Positive numbers: 0 to 7F (0 to 127) Negative numbers: 80 to FF (-1 to -128) All negative numbers are represented in2’s complementData Format (8-bit) (3 of 4)n Binary Coded Decimal Numbers (BCD) 8bits of a number divided into groups of four,and each group represents a decimal digitfrom 0 to 9 Four-bit combinations from A through F in Hexare invalid in BCD numbersn Example: 0010 0101 represents the binary codingof the decimal number 25d which is different invalue from 25H.19

9/27/14Data Format (8-bit) (4 of 4)n American Standard Code for InformationInterchange (ASCII) Seven-bitalphanumeric code with 128combinations (00 to 7F) Represents English alphabet, decimal digitsfrom 0 to 9, symbols, and commandsStoring Bits in Memoryn We can store in different memorytypesn In an 8-bit RAM EEPROM, FLASH, RAM, etc.Each byte is stored in a singlememory registerEach word is stored in two memorylocations (registers)DATA 0x1234n 0x12à REG11 (High-order byte)n 0x34à REG10 (Low-order byte) 0001 00100011 0100Whatif we1000wantstore complement)-8?Remember-8à 111(intotwo’s20

9/27/14Design Examples .Microcontrollers vs. MicroprocessorsMPU-Based Timeand Temperature System21