MICROPROCESSOR, MICROCOMPUTER AND ASSEMBLY LANGUAGE INTRODUCTION TO MICROPROCESSOR AND MICROCOMPUTER Reported by: Abanador, Ma. Kristine Joy MICROPROCESSOR Amicroprocessorisacomputerprocessor thatincorporatesthefunctionsofa computer's central processing unit(CPU) on a single integrated circuit(IC), or at most a few integrated circuits. Themicroprocessorisamultipurpose, programmabledevicethatacceptsdigital dataasinput,processesitaccordingto instructionsstoredinitsmemory,and provides results as output. MICROPROCESSOR Electronic circuit that functions as the central processing unit (CPU) of a computer Designed to perform arithmetic and logic operations Can be classified by Semiconductor technology of the design Width of the data format Instruction set Semiconductor Technology of the design TTL Transistor-Transistor Logic uses bipolar transistors to form its integrated circuits Most commonly used ECL Emitter-Coupled Logic Digital technology with extremely high-speed CMOS Complementary-Metal-Oxide Semiconductor Favored for portable computers and battery powered devices Has low power consumption Width of the Data format 4-bit, 8-bit, 16-bit, 32-bit or 64-bit The wider the data format, the faster and more expensive the device. Complex Instruction Set Computer (CISC), Reduced Instruction Set Computer (RISC) Instruction Set MICROCOMPUTER A computer that depends on a microprocessor (Personal Computer) Designed to be used by individuals, whether in the form of PCs, workstations or notebook computers Contains aCPU on a microchip, a memory system, a bus system, and I/O ports Intels first microcomputer appeared in 1971: MCS-4 emphasizing low cost (November 1971) MSC-8 for versatility (April 1972) Intel MCS-4 Designed for applications such as test systems, peripherals, terminals, billing machines, measuring systems, numeric and process control Interface easily with switches, keyboards, displays, teletypewriters, printers, readers, A-D converters and other peripherals Fabricated with Silicon Gate Technology 10.8 s Instruction cycle time Intel MCS-4 4-B Chip Set The MCS-4 is family of 4 chipshoused in 16 - pin packages, developedby Intel, which includes the following: 4001 (ROM) 4002 (RAM) 4003 (Shift Register) 4004 (Microprocessor) Intel MCS-4 Can have up to: 4K x 8 bit ROM words 1280 x 4 bit RAM characters 128 I/O lines without requiring any interface logic Powerful Instruction set allows both binary and decimal arithmetic, and includes conditional branching, jump to subroutine, and provides 4001 ROM Chip AsaROM,itcontainsthecustom microprogramandisimplementedusing ametalmaskaccordingtocustomer specifications Organized as 256 x 8 bit words Hadanintegratedaddressregister,an outputdataregister,multiplexers,and control timing logic Secondmodeofoperation:Asan Input/Output control device 4001 ROM Chip 4002 (RAM Chip) 4002 performs two functions: 1. As a RAM, it stores 320 bit arranged in 4 registers of 20 4-bit characters each 2. As a vehicle of communication with peripheral devices, it is provided with 4 output lines and associated control logic to perform output operations Had an integrated address register, an output data register, multiplexers, and control timing logic A built-in refresh counter was used to maintain data integrity 4002 RAM 4003 SHIFT REGISTER A10bitstaticshiftregisterwith serial in, parallel- out and serial-out data Foroutputportexpansion,to interfacewithI/Odevicessuchas keyboards,displays,printers, teletypewriters,switches,readers, A-D converters, etc 4003 SHIFT REGISTER 4004 MICROPROCESSOR A central processor unit (CPU) designed to work in conjunction with the other members of the MCS-4 for microprogrammable computer application CPU chip consists of a 4 bit adder, a 64 bit (16 x 4) index register, a 48 bit (4 x 12) program counter and stack, and address decrementer, an 8 bit instruction register and decoder and control logic Contains 5 command control lines: 1 command ROM control line and 4 command RAM control lines 4004 MICROPROCESSOR BASIC SYSTEM OPERATION OF MCS-4 CPU generates SYNC to the ROMs and RAMs. Basic instruction execution requires 8 or 16 cycles of 750kHz clock In the first 3 cycles: CPU sends 12 bits of address to the ROMs In the next 2 cycles: The selected ROM chip sends back 8 bits of instruction to the CPU In the final 3 cycles: The instruction is then interpreted and executed The ROM bank is controlled by a command ROM control signal and up to four RAM banks are controlled by four command RAM control signals BASIC SYSTEM OPERATION OF MCS-4 When a RAM instruction is executed, the address of a RAM chip, register and character which is stored in two index registers in the CPU is transferred to the RAM. When the RAM output instruction is received by the CPU, the content of the CPU accumulator is transferred to the four RAM output lines The CPU, RAMs and ROMs can be controlled by an external RESET line MCS-4 APPLICATION Busicom of Japan produced several calculator models using the MCS-4 chip set Ted Hoff- made the original proposal for MCS 4 and did feasibility study for first calculator Federico Faggin- did all ofthe logic and circuit design and implemented the layout M. Shima (from Busicom)-wrote most of the firmware Intel patent on the MCS-4 has 17 claims MCS-4 evolved into the single chip microcomputers INTEL 8008 TheIntel8008istheworld'sfirst8bit microprocessor introduced in April 1972. ThedeveloperswereTedHoff,Stan Mazor,HalFeeney,andFederico Faggin. InteldesigneditforComputerTerminal Corporation(CTC)foruseinits Datapoint2200terminal,butbecause the 8008 was delivered too late and did notmeetCTC'sexpectations,they didn'tusedit.Intelthenbroughtthe rightsbackandmarketedthechipon its own. INTEL 8008 Technology: P- MOS Transistors: 3,500 An8-bCPU,packagedin18-pinDIP,implementedwithTTLandhad48data processing instructions Hadan8-bdatabusandexternal14-b addressbus,whichcanaddress16KBof memory Hadonememoryaddressspacefor program and data INTEL 8008 Eight8-bit"scratchpad"registers:The mainaccumulator(A)andsevenother registers (B, C, D, E, H, and L) Indirect memory access using the H and Lregisters(HL)asa14-bitdatapointer providing a virtual register M. Abuilt-inhiddenrefreshcounterwas used to maintain data integrity Separate from the memory, 8 input ports and 24 output ports can be accessed INTEL 8008 Amemorystackcontaininga14-bit ProgramCounterisusedinternallyto store program and subroutine addresses Seven-level push-down address call stack. Eight registers are actually used, with the top-most register being the PC. Four condition code status flags: Carry (C), even Parity (P), Zero (Z), and Sign (S). Utilized standard memory components (not ROM and RAM) Instruction cycle time of 20s INTEL 8008 INTEL 8008 Byte Ordering Little Endian In Little-Endian systems, the least significant byte of a multi-byte data item has the lowest address, while the most significant byte has the highest address. Applications Seiko (Japan) used 8008 for a sophisticated scientific calculator Used in business machines and a variety of general purpose computers INTEL 8080 The Intel 8080 was the second 8-bit microprocessor and manufactured by Intel and was released in April 1974. It was an extended and enhanced variant of the earlier 8008 design. The architecture of the 8080 strongly influenced Intel's 8086 CPU architecture, which spawned the x86 family of processors. INTEL 8080 Technology: N Mos Transistors: 6,000 (6 micron) Usednon-saturatedenhancement loadNMOSgateimplementation, thechipneededmultipleinput voltages: -5V, +5V and +12V. Has16-bitaddressbus,8-bit bidirectionaldatabusandfully decoded,TTLcompatiblecontrol outputspackagedina40-pinDIP packaging,allowingeasyaccessto 64 KB of memory. INTEL 8080 Hasseven8-bitregisters(A,B,C,D,E, H,andL),whereAistheprimary8-bit accumulator and the other six registers canbeusedaseitherindividual8-bit registers or as three 16-bit register pairs (BC,DE,andHL)dependingonthe particular instruction Hasa16-bitStackPointertomemory and a 16-bit Program Counter INTEL 8080 Status Register, the flags are: Sign (S), set if the result is negative Zero (Z), set if the result is zero Parity (P), set if the number of 1 bits in the result is even Carry (C), set if the last addition operation resulted in a carry, or if the last subtraction operation required a borrow Auxiliary carry (AC or H), used for binary-coded decimal arithmetic INTEL 8080 Canaddressupto256inputports and 256 output ports Offerstheuserahighperformance solutiontocontrolandprocessing applications Powerfulproblemsolvinginstruction set Significantfeature:SPEED(2s Instruction cycle time) INTEL 8080 INTEL 8085 Technology: N Mos (later AH models used HMOS) Transistors: 6,500 (6 micron) An8-bitCPUpackagedina40-pin dualinlinepackage(DIP),Binary compatible 8-bitdatabusmultiplexedwiththe lowerpartofthe16-bitaddressbus and up to 64KB memory INTEL 8085 Hasseven8-bitregisters(A,B,C,D,E, H,andL),whereAistheprimary8-bit accumulator and the other six registers canbeusedaseitherindividual8-bit registers or as three 16-bit register pairs (BC,DE,andHL)dependingonthe particular instruction Hasa16-bitStackPointertomemory and a 16-bit Program Counter Can address up to 256 input ports and 256 output ports INTEL 8085 It requires a single +5V power supply Has4VectoredInterrupts(OneisNon Maskable) Serial In/Serial Out Port Decimal,Binary,andDoublePrecision Arithmetic DirectAddressingCapabilityto64K bytes of memory Clock oscillator integrated in the chip INTEL 8085 INTEL 8086 Intel 8086 is a 16-bit microprocessor chip designed by Intel between early 1976 and mid-1978, when it was released. 8086 gave rise to the x86 architecture which eventually became Intel's most successful line of processors. Technology: N Mos Transistors: 29,000 (3 micron) INTEL 8086 A16-bitmicroprocessorwhichhas16 bitALU,16bitregistersandinternal data bus and 16 bit external data bus 8086has20bitaddresslinesto accessmemory.Henceitcan access 1 MB memory location 8086has16-bitaddresslinesto accessI/Odevices,henceitcan access 64K I/O location INTEL 8086 Thedatabusismultiplexedwiththe addressbusinordertofitallofthe controllinesintoastandard40-pin dual in-line package INTEL 8086 Operates in two modes: 8086 operates in two modes: a)Minimum Mode: A system with only one microprocessor. b)Maximum Mode:-A system with multiprocessor. 8086 uses memory banks The 8086 uses a memory banking system. It means entire data is not stored sequentially in a single memory of 1 MB but memory is divided into two banks of 512KB INTEL 8086 8086 has a 16-bit flags register Nine of these condition code flags are active, and indicate the current state of the processor: Carry flag (CF), Parity flag (PF), Auxiliary carry flag (AF), Zero flag (ZF), Sign flag (SF), Trap flag (TF), Interrupt flag (IF), Direction flag (DF), and Overflow flag (OF). INTEL 8086 Interrupts 8086 has 256 vectored interrupts. Multiplication And Division 8086 has a powerful instruction set. It supports Multiply and Divide operation. INTEL 8086 8086providesanadditionalfeature thatithasaninstructionqueue capabletostoresixinstructionbytes fromthememory.Thenextinstruction isfetchedwhilethepresentinstruction is being executed. INTEL 8088 TheIntel8088microprocessorisa variant of the Intel 8086. It was released in 1979 Bothprocessorshadfundamentallythe same architecture, but the 8088 had an 8-bitexternaldatabusinsteadof the16-bitbusofthe8086.The16-bit registersandthe1MBaddressrange were unchanged Technology: N Mos Transistors: 29,000 (3 micron) INTEL 8088 The original IBM PC was based on the 8088 Asaresult,the8088CPUusedtwo consecutivebuscyclestoreador write16bitdata,insteadofonebus cycle for the 8086, which reduced the performanceofthe8088compared to the 8086. INTEL 8088 The benefit of the 8088 was that the hardwarechangesmadeit compatiblewith8080/8085support chips,whichwasanimportant factorforIBMinchoosingthe8088 topowerit'sIBMPClineof computers,becauseatthattime8-bitsupportchipswerecheaper than their 16-bit counterparts. INTEL 8088 Otherthantheexternaladdressbus width, the processor was logically and functionally identical to the 8086