COSC 3406: Computer Organization Kalpdrum Passi ( www.cs.laurentian.ca/kpassi/cosc3406.html )

Morgan Kaufmann Publishers Computer Abstractions and Technology Chapter 1 — Computer Abstractions and Technology November 11, 2018 Morgan Kaufmann Publishers Chapter 1 Computer Abstractions and Technology

Morgan Kaufmann Publishers Chapter 1 — Computer Abstractions and Technology November 11, 2018 Morgan Kaufmann Publishers Below Your Program Application software Written in high-level language System software Compiler: translates HLL code to machine code Operating System: service code Handling input/output Managing memory and storage Scheduling tasks & sharing resources Hardware Processor, memory, I/O controllers

Morgan Kaufmann Publishers Chapter 1 — Computer Abstractions and Technology November 11, 2018 Morgan Kaufmann Publishers Levels of Program Code High-level language Level of abstraction closer to problem domain Provides for productivity and portability Assembly language Textual representation of instructions Hardware representation Binary digits (bits) Encoded instructions and data

Levels of Representation temp = v[k]; v[k] = v[k+1]; v[k+1] = temp; High Level Language Program (e.g., C) Compiler lw $t0, 0($2) lw $t1, 4($2) sw $t1, 0($2) sw $t0, 4($2) Assembly Language Program (e.g.,MIPS) Assembler Machine Language Program (MIPS) 0000 1001 1100 0110 1010 1111 0101 1000 1010 1111 0101 1000 0000 1001 1100 0110 1100 0110 1010 1111 0101 1000 0000 1001 0101 1000 0000 1001 1100 0110 1010 1111 Machine Interpretation wire [31:0] dataBus; regFile registers (databus); ALU ALUBlock (inA, inB, databus); Hardware Architecture Description (e.g., Verilog Language) Architecture Implementation wire w0; XOR (w0, a, b); AND (s, w0, a); Logic Circuit Description (Verilog Language)

Components of a Computer Chapter 1 — Computer Abstractions and Technology November 11, 2018 Morgan Kaufmann Publishers Components of a Computer §1.4 Under the Covers Same components for all kinds of computer Desktop, server, embedded Input/output includes User-interface devices Display, keyboard, mouse Storage devices Hard disk, CD/DVD, flash Network adapters For communicating with other computers The BIG Picture

Morgan Kaufmann Publishers Chapter 1 — Computer Abstractions and Technology November 11, 2018 Morgan Kaufmann Publishers Touchscreen PostPC device Supersedes keyboard and mouse Resistive and Capacitive types Most tablets, smart phones use capacitive Capacitive allows multiple touches simultaneously

Through the Looking Glass Chapter 1 — Computer Abstractions and Technology November 11, 2018 Morgan Kaufmann Publishers Through the Looking Glass LCD screen: picture elements (pixels) Mirrors content of frame buffer memory

Morgan Kaufmann Publishers Chapter 1 — Computer Abstractions and Technology Morgan Kaufmann Publishers November 11, 2018 Opening the Box Capacitive multitouch LCD screen 3.8 V, 25 Watt-hour battery Computer board Integrated Circuits

Inside the Processor (CPU) Chapter 1 — Computer Abstractions and Technology November 11, 2018 Morgan Kaufmann Publishers Inside the Processor (CPU) Datapath: performs operations on data Control: sequences datapath, memory, ... Cache memory Small fast SRAM memory for immediate access to data

Morgan Kaufmann Publishers Chapter 1 — Computer Abstractions and Technology November 11, 2018 Morgan Kaufmann Publishers Inside the Processor Apple A5

Morgan Kaufmann Publishers Chapter 1 — Computer Abstractions and Technology November 11, 2018 Abstractions The BIG Picture Abstraction helps us deal with complexity Hide lower-level detail Instruction set architecture (ISA) The hardware/software interface Application binary interface (ABI) The ISA plus system software interface (operating system) Implementation The details underlying and interface Hardware that obeys the architecture abstraction

Abstractions Instruction Set Architecture or architecture (ISA) Interface between hardware and the lowest-level software Anything programmers need to know to make a binary machine language program work correctly Application Binary Interface (ABI) Combination of basic instruction set and the operating system interface provided for application programmers Architecture Vs Organization Architecture (ISA) – abstraction Organization – implementation of ISA in hardware

Overview of Physical Implementations The hardware out of which we make systems. Integrated Circuits (ICs) Combinational logic circuits, memory elements, analog interfaces. Printed Circuits (PC) boards substrate for ICs and interconnection, distribution of CLK, Vdd, and GND signals, heat dissipation. Power Supplies Converts line AC voltage to regulated DC low voltage levels. Chassis (rack, card case, ...) holds boards, power supply, provides physical interface to user or other systems. Connectors and Cables.

Morgan Kaufmann Publishers Chapter 1 — Computer Abstractions and Technology November 11, 2018 Morgan Kaufmann Publishers A Safe Place for Data Volatile main memory Loses instructions and data when power off Non-volatile secondary memory Magnetic disk Flash memory Optical disk (CDROM, DVD)

Great Idea: Principle of Locality/ Memory Hierarchy 11/11/2018 16

Morgan Kaufmann Publishers Chapter 1 — Computer Abstractions and Technology November 11, 2018 Morgan Kaufmann Publishers Networks Communication, resource sharing, nonlocal access Local area network (LAN): Ethernet Wide area network (WAN): the Internet Wireless network: WiFi, Bluetooth

Morgan Kaufmann Publishers November 11, 2018 Chapter 1 — Computer Abstractions and Technology Technology Trends Electronics technology continues to evolve Increased capacity and performance Reduced cost §1.5 Technologies for Building Processors and Memory DRAM capacity Year Technology Relative performance/cost 1951 Vacuum tube 1 1965 Transistor 35 1975 Integrated circuit (IC) 900 1995 Very large scale IC (VLSI) 2,400,000 2013 Ultra large scale IC 250,000,000,000

Semiconductor Technology Silicon: semiconductor (found in sand) Add materials to transform properties: Conductors (using either microscopic copper or aluminum wire) Insulators (like plastic sheathing or glass) Switch (Areas that can conduct or insulate under specific conditions) Transistors fall into the last category. A VLSI circuit, is just billions of combinations of conductors, insulators, and switches manufactured in a single small package.

Morgan Kaufmann Publishers Chapter 1 — Computer Abstractions and Technology November 11, 2018 Morgan Kaufmann Publishers Manufacturing ICs Yield: proportion of working dies per wafer

Morgan Kaufmann Publishers Chapter 1 — Computer Abstractions and Technology November 11, 2018 Morgan Kaufmann Publishers Intel Core i7 Wafer 300mm wafer, 280 chips, 32nm technology Each chip is 20.7 x 10.5 mm

Integrated Circuit Cost Chapter 1 — Computer Abstractions and Technology November 11, 2018 Morgan Kaufmann Publishers Integrated Circuit Cost Nonlinear relation to area and defect rate Wafer cost and area are fixed Defect rate determined by manufacturing process Die area determined by architecture and circuit design

Morgan Kaufmann Publishers Chapter 1 — Computer Abstractions and Technology November 11, 2018 Defining Performance §1.6 Performance Which airplane has the best performance?

Response Time and Throughput Chapter 1 — Computer Abstractions and Technology November 11, 2018 Morgan Kaufmann Publishers Response Time and Throughput Response time How long it takes to do a task Throughput Total work done per unit time e.g., tasks/transactions/… per hour How are response time and throughput affected by Replacing the processor with a faster version? Adding more processors? We’ll focus on response time for now…

Morgan Kaufmann Publishers Chapter 1 — Computer Abstractions and Technology November 11, 2018 Morgan Kaufmann Publishers Relative Performance Define Performance = 1/Execution Time “X is n time faster than Y” Example: time taken to run a program 10s on A, 15s on B Execution TimeB / Execution TimeA = 15s / 10s = 1.5 So A is 1.5 times faster than B

Measuring Execution Time Chapter 1 — Computer Abstractions and Technology November 11, 2018 Morgan Kaufmann Publishers Measuring Execution Time Elapsed time Total response time, including all aspects Processing, I/O, OS overhead, idle time Determines system performance CPU time Time spent processing a given job Discounts I/O time, other jobs’ shares Comprises user CPU time and system CPU time Different programs are affected differently by CPU and system performance

Morgan Kaufmann Publishers Chapter 1 — Computer Abstractions and Technology Morgan Kaufmann Publishers November 11, 2018 CPU Clocking Operation of digital hardware governed by a constant-rate clock Clock period Clock (cycles) Data transfer and computation Update state Clock period: duration of a clock cycle e.g., 250ps = 0.25ns = 250×10–12s Clock frequency (rate): cycles per second e.g., 4.0GHz = 4000MHz = 4.0×109Hz

Morgan Kaufmann Publishers Chapter 1 — Computer Abstractions and Technology November 11, 2018 Morgan Kaufmann Publishers CPU Time Performance improved by Reducing number of clock cycles Increasing clock rate Hardware designer must often trade off clock rate against cycle count

Morgan Kaufmann Publishers Chapter 1 — Computer Abstractions and Technology November 11, 2018 Morgan Kaufmann Publishers CPU Time Example Computer A: 2GHz clock, 10s CPU time Designing Computer B Aim for 6s CPU time Can do faster clock, but causes 1.2 × clock cycles How fast must Computer B clock be?