Embedded Systems Lesson 4 (Embedded Processors) PDF

Embedded Systems Lesson 4 (Embedded Processors) INTRODUCTION Basic characteristics of an embedded system: - system built to perform its duty, completely or partially independent of human...

Embedded Systems Lesson 4 (Embedded Processors) INTRODUCTION Basic characteristics of an embedded system: - system built to perform its duty, completely or partially independent of human intervention - designed to perform a few tasks in the most efficient way - interacts with physical elements in our environment - an embedded system is designed to be more compact, energy efficient, and inexpensive - exhibit single tasking and multitasking capabilities - contain processing cores that are typically either microcontrollers or digital signal processors (DSP) being dedicated to handle a particular task can be optimize it to reduce the size and cost and increase the reliability and performance range from portable devices to large stationary installations complexity varies from low, with a single microcontroller chip, to very high with multiple units, peripherals and networks more and more of the stuff that was once “peripheral logic” has been integrated on the same chip as the CPU  Important parts of an embedded processor are mentioned below - CPU - I/O ports - RAM: contains temporary data - ROM: contains program and constant data – the firmware, use Flash memory instead of true ROM to hold the firmware - Timers - Serial interface: often a USART - EEPROM: contains “permanent” data - Analog-to-digital converter - Digital to analog converter PROCESSORS first microprocessor was developed by INTEL Corporation in 1971 in the brand name of INTEL 4004 - 4 bit microprocessor designed with large scale integration (LSI) technology - number of instruction of INTEL 4004 was 45 - fabricated by P-MOS technology - rate of execution 50 KIPS (Kiloinstruction per second)  other 4 bit microprocessors - PPS- 4 byRockwell international - T 3472 by Toshiba - TMS-1000 by Texas instruments 1972 INTELproduced the first 8 bit microprocessor INTEL 8008 - address an expanded memory size of 16 Kilobytes and 48 instructions 1973 INTEL-Corporation produced INTEL 8080 - fabricated by NMOS technology - ten times faster than 8008 microprocessor (500 KIPS) - memory capacity of INTEL 8080 is 64 KB  In 1975 INTEL produced INTEL 8085 - execution rate is 769.23KIPS - own internal clock generator and internal system controller - can execute 246 instructions 1978 when INTEL introduced a 16 bit microprocessor INTEL 8086 after one year, INTEL Corporation released 8088  - can address one Megabyte of memory location - execution speed of 8086 microprocessor is 2.5 million instructions per second (MIPs) - popular to use in microcomputer applications - speed of execution increased by using instruction queue or cache - number of instructions of this microprocessor is about 20,000, known as complex instruction set computers(CISC) - have more internal registers - 16 bit registers help to write program efficiently CISC microprocessor causes reduction in computing speed of microprocessors reduced instruction set computer (RISC) microprocessor is developed to increase computing speed using hardwired control unit  RISC microprocessors available in the market - PowerPC 601.603, 604 etc - Intel’s PA8000 - DEC’s Alpha21064 - SUN’s SPARC etc CISC microprocessors - Intel’s 486, Pentium - Pentium Pro - Pentium II - Celeron - Pentium III - Pentium IV - Motorola 68000 etc Intel introduced 80186 microprocessor - not at all popular for general purpose computers - used for only industrial control  Intel produced microprocessor 80286 - 24 line address bus, can provide address for 16 MB memory - clock speed is 8 MHz - execution rate 4 MIPS 1986 INTEL Corporation introduced 32 bit processor 80386 - 32 bit data bus and 32 bit memory address bus - memory capacity of this processor is 4 GB (Gigabyte) - suitable for graphic user interface (GUI) and Computer Aided Design (CAD) - includes hardware circuitry for memory management assignment  1989 INTEL Corporation introduced 80486 microprocessor - incorporates 80386 like microprocessor, 80387 like numeric coprocessor and 8 KB cache memory in the same integrated circuit package - clock speed of 50 MHz to 66 MHz - instruction execution rate is 50 MIPS - expandable16 KB cache memory - tripled clock version increases the speed 120 MH - has 32 line address bus  1993 INTEL Corporation introduced 64 bit Pentium (P5) microprocessor using super scalar technology - execution rate of this processor is 110 MIPS - clock frequency is100MHz - Double clocked version of Pentium processor operates at 133 MHz - cache memory of this processor is increased to 16 KB - 64 bit data bus - memory size of Pentium processor is 4 GB - executes two instructions simultaneously per clock period - JUMP prediction technology is included - includes internal floating point coprocessor in the same integrated circuit package  Pentium pro-microprocessor (P6) was also introduced by INTEL - contains 21 million transistors - three integer units and one floating point unit - clock frequency of Pentium pro-microprocessor is 166 MHz - 64 bit data bus - 64GB main memory - 16 KBL1 cache and 256 KB L2 cache - employs three execution engines - 36 bit address bus for 64 GB memory system