Архитектура ЭВМ. Лекция 0: Предварительные сведения

Introduction and Course Overview

In this section, Kirill Kalinkin introduces himself and the course on computer architecture. He explains his goals for the course and what he hopes students will achieve.

Introduction to Computer Architecture

• Kirill Kalinkin introduces himself as the instructor for the course on computer architecture.

• The goal of the course is to provide a deep understanding of how computers work, starting from the basics of electrical engineering.

• Students are encouraged to gain knowledge about electric current and how it relates to computer functioning.

• The course aims to enable students to build their own computers or perform mental experiments with computer components.

• Kirill mentions that they will start with a brief history of computing machines.

History of Computing Machines

In this section, Kirill discusses the earliest computing machines and their purpose. He highlights that these early devices were not exactly computers but rather counting machines.

Ancient Computing Machines

• The earliest known computing machine was called an abacus, which was used for counting.

• These early devices were not true computers but rather simple counting tools without any programmability.

• Kirill emphasizes that these early machines were different from modern computers as they lacked universality in their operations.

Mechanical Computers and Charles Babbage

This section focuses on mechanical computers and Charles Babbage's contributions to computer development. It highlights that mechanical computers had limited programmability compared to modern digital computers

Understanding Power Sources and Components

In this section, the speaker discusses power sources and components used in electronic circuits.

Power Sources

• A power source has a positive (+) and negative (-) terminal.

• Batteries are commonly used as power sources.

• The longer terminal of a battery is the positive (+) terminal, while the shorter one is the negative (-) terminal.

Capacitors

• Capacitors store charge and do not allow current to pass through them.

• They accumulate charge, which can be released later.

• Capacitors are represented by two parallel lines in circuit diagrams.

Diodes

• Diodes allow current to flow in one direction but block it in the opposite direction.

• Current flows from the anode (positive side) to the cathode (negative side).

• Diodes are often represented by an arrow pointing towards the cathode.

LEDs (Light Emitting Diodes)

• LEDs are a type of diode that emit light when current passes through them.

• They are energy-efficient and commonly used as indicators or small light sources.

Introduction to Circuits and Components

This section introduces circuits, components, and their behavior.

Bulbs/Lamps

• Bulbs or lamps illuminate when current flows through them.

• They do not light up when there is no current passing through.

Transistors

• Transistors are another type of component used in circuits.

• Their behavior will be discussed later in more detail.

Understanding the Flow of Water and Time

In this section, the speaker discusses the flow of water and how it relates to the concept of time. They explain that as the width of a pipe increases, the flow rate decreases, highlighting extreme cases to illustrate this concept.

The Relationship Between Energy and Potential

• The speaker explains that energy stored in a battery is mainly potential energy, which flows through a circuit. If an ideal conductor is used, no energy will be lost.

• They mention that the voltage across a conductor determines the current flowing through it according to Ohm's law.

Short Circuits and Extreme Cases

• The speaker introduces the concept of short circuits, where two contacts are connected directly. They note that short circuits can cause heating but caution against attempting them with certain types of batteries.

• They explain that different electronic components have specific voltage ranges for operation. For example, an LED requires a certain voltage range to function properly.

Managing Current with Resistors

• The speaker discusses the need for resistors when connecting LEDs or other components to prevent excessive current flow. They mention calculating resistor values based on desired voltages.

• They compare resistors connected in series and parallel configurations, explaining how current distribution differs between them.

Analogies for Understanding Electrical Concepts

• Using analogies with pipes of different diameters, they illustrate how current behaves in series and parallel connections.

• The speaker emphasizes that understanding electrical concepts is not limited to complex calculations but also involves grasping fundamental principles.

Introduction to Electronic Computing

• They introduce the idea of electronic computing and its reliance on human control of electric current flow.

• The speaker mentions that early electronic computers were built using relays, which can be considered as advanced switches controlled by electric current.

Electronic Components: Vacuum Tubes

• They explain the structure of a vacuum tube, consisting of a cathode and an anode connected by a grid.

The Role of Electrons in Conductivity

This section discusses the role of electrons in conductivity and how they act as charge carriers. It explains that electrons flow from the cathode to the anode, and by applying voltage to the grid, their movement can be controlled.

Understanding Electron Flow in Conductivity

• Electrons are responsible for conductivity and act as charge carriers.

• Electrons flow from the cathode to the anode.

• By applying voltage to the grid, electron movement can be controlled.

Controlling Electron Flow with Voltage

This section explains how electron flow can be controlled by applying voltage to the grid. It describes how increasing voltage on the grid can amplify electric current.

Controlling Electron Flow with Voltage

• Applying voltage to the grid causes electrons to move towards the anode.

• Increasing voltage on the grid amplifies electric current.

Transistors as Amplifiers

This section introduces transistors as amplifiers and compares them to electronic tubes. It explains that transistors work similarly to electronic tubes but are smaller and cheaper.

Transistors as Amplifiers

• Transistors work similarly to electronic tubes.

• They are smaller and cheaper than electronic tubes.

• Transistors can amplify signals by controlling conductivity.

Understanding Transistor Functionality

How Capacitors Work

In this section, the speaker explains how capacitors work and their role in electronic circuits.

Capacitor Functionality

• A capacitor is a component that stores and releases electrical energy.

• It changes its behavior over time, gradually charging and discharging.

• The capacitor affects the voltage curve of a circuit by delaying or altering it.

• It can be used to create filters that smooth out unstable voltages.

Capacitor Charging and Discharging

• When a capacitor charges, it absorbs energy from the circuit until it reaches a certain voltage level.

• Once charged, the capacitor can release energy back into the circuit when needed.

• If there are fluctuations in voltage, the capacitor compensates by providing additional energy to stabilize it.

Applications of Capacitors

• Capacitors are commonly used in filters to remove unwanted noise or ripple from power supplies.

• They play a crucial role in digital systems where signals need to be converted between analog and digital formats.

• Capacitors are essential components for building complex electronic circuits.

Introduction to Operational Amplifiers (Op-Amps)

This section introduces operational amplifiers (op-amps) and their significance in signal processing.

Op-Amp Basics

• An op-amp is an electronic device that amplifies signals with high gain and accuracy.

• Op-amps are vital for converting analog signals into digital ones used by computers.

Signal Representation

• Signals in electronics are represented as binary values: 0s and 1s.

• In reality, signals vary continuously rather than being discrete values like 0 or 1.

Importance of Op-Amps

Understanding Signal Levels and Switching Speed

In this section, the speaker discusses signal levels and switching speed in electronic circuits. They explain how the voltage level of a signal affects its behavior and the importance of understanding the speed at which signals switch.

Signal Levels and Voltage Scale

• Signals are represented by voltage levels, with 0 representing a low level and 1 representing a high level.

• The voltage scale is divided into different ranges, with some signals having a wider range than others.

• It is important to note that there is a range where the signal is undefined, neither 0 nor 1.

Impact of Switching Speed

• The speed at which signals switch between 0 and 1 is crucial for electronic devices' performance.

• Voltage does not instantly transition from 1 to 0 or vice versa; there is always a small time delay during switching.

• Electronic components are designed to make signal switching as predictable as possible for optimal performance.

Comparing Signals

• Signals should not be compared based on their nominal values alone (e.g., comparing two signals both labeled as "1").

• In reality, signals can have variations due to factors like noise or interference.

• It's essential to consider the entire waveform when comparing signals rather than just their nominal values.

Floating Contacts

• Floating contacts refer to unconnected contacts in an electronic circuit.

• These contacts can pick up stray signals from the environment, leading to unstable behavior in circuits.

• To avoid issues caused by floating contacts, it

History and Principles of Computer Architecture

In this section, the speaker discusses the history and principles of computer architecture, specifically focusing on the development of electronic computers and the two main architectures - Harvard and von Neumann.

Development of Computer Architecture

• The origins of computer architecture can be traced back to military agencies in the United States, such as DARPA.

• The goal was to build electronic computers based on general principles of computer construction.

• Two architectures emerged from this development: Harvard architecture and von Neumann architecture.

Principles of Computer Architecture

• There are three key principles that should be followed when designing a computer architecture:

• The computer should consist of memory and a processor, with addressable memory cells.

• Memory should be homogeneous, meaning that addresses should be continuous without gaps.

• The computer should have program control to manage data stored in memory.

Harvard vs. von Neumann Architecture

• Harvard architecture and von Neumann architecture are visually similar but differ in one aspect.

• In Harvard architecture, instructions and data are stored in separate memories connected by address and data buses.

• In von Neumann architecture, instructions and data share the same memory space.

Advantages and Disadvantages of Harvard Architecture

This section explores the advantages and disadvantages of using Harvard architecture in computer systems.

Advantages

• Separate instruction and data memories allow for simultaneous access to both types of information.

• This can lead to faster execution times since fetching instructions does not interfere with accessing data.

Disadvantages

• Using separate memories requires more physical space compared to von Neumann architecture.

• It also requires additional complexity in terms of addressing schemes and bus connections.

Overview of Processor Functionality

The speaker provides an overview of how a processor functions and its basic components.

Processor Components

• A processor consists of a computational unit (ALU) and memory.

• The ALU performs operations on instructions and their arguments, storing the results back in memory.

• The processor has a pointer to the current memory cell where instructions are stored.

• It retrieves instructions, executes them, and moves to the next memory cell.

Conclusion

The speaker concludes by emphasizing that processors are simple machines that follow a basic model. They have a computational unit, memory, and operate by fetching instructions, executing them, and moving to the next instruction.

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