4.3 Input-Output organization and multiprocessor

4.3 Input-Output organization and multiprocessor: 

 

Peripheral devices 

Which of the following is NOT considered a peripheral device?

a) Keyboard

b) CPU

c) Printer

d) Mouse

Answer: b) CPU

Explanation: Peripheral devices are external hardware components connected to a computer system, such as keyboards, printers, and mice. The CPU (Central Processing Unit) is the primary processing unit of the computer and is not considered a peripheral device.

Which peripheral device is commonly used for long-term data storage?

a) Scanner

b) Monitor

c) Hard disk drive

d) Microphone

Answer: c) Hard disk drive

Explanation: Hard disk drives are commonly used for long-term data storage, providing non-volatile storage for operating systems, applications, and user data.

Which peripheral device is responsible for converting digital signals from the computer into analog signals for transmission over telephone lines?

a) Modem

b) Webcam

c) Scanner

d) Graphics tablet

Answer: a) Modem

Explanation: A modem (Modulator-Demodulator) is a peripheral device that converts digital signals from the computer into analog signals for transmission over telephone lines and vice versa.

Which peripheral device is commonly used for capturing images and documents in digital format?

a) Printer

b) Scanner

c) Webcam

d) Plotter

Answer: b) Scanner

Explanation: Scanners are peripheral devices used for capturing images and documents in digital format, allowing users to create electronic copies of physical documents.

Which peripheral device is responsible for producing a hard copy of electronic documents or images?

a) Scanner

b) Printer

c) Plotter

d) Webcam

Answer: b) Printer

Explanation: Printers are peripheral devices used for producing hard copies of electronic documents or images on paper or other media.

Which peripheral device is commonly used for capturing video footage and transmitting it over the internet?

a) Scanner

b) Printer

c) Webcam

d) Plotter

Answer: c) Webcam

Explanation: Webcams are peripheral devices equipped with a camera and microphone, commonly used for capturing video footage and transmitting it over the internet for video conferencing, streaming, and recording purposes.

Which peripheral device is responsible for capturing and converting audio signals into digital format?

a) Printer

b) Plotter

c) Microphone

d) Scanner

Answer: c) Microphone

Explanation: Microphones are peripheral devices used for capturing audio signals and converting them into digital format for recording, voice recognition, and communication purposes.

Which peripheral device is commonly used for creating large-scale drawings, designs, or blueprints?

a) Printer

b) Scanner

c) Webcam

d) Plotter

Answer: d) Plotter

Explanation: Plotters are peripheral devices used for creating large-scale drawings, designs, or blueprints by drawing continuous lines on paper or other media based on digital instructions.

Which peripheral device is responsible for capturing biometric data such as fingerprints or iris scans?

a) Scanner

b) Printer

c) Plotter

d) Biometric sensor

Answer: d) Biometric sensor

Explanation: Biometric sensors are peripheral devices used for capturing biometric data such as fingerprints, iris scans, or facial recognition for authentication and security purposes.

Which peripheral device is commonly used for capturing handwritten input and converting it into digital format?

a) Printer

b) Scanner

c) Webcam

d) Graphics tablet

Answer: d) Graphics tablet

Explanation: Graphics tablets, also known as digitizing tablets or drawing tablets, are peripheral devices used for capturing handwritten input and drawings by detecting the movement of a pen or stylus on a flat surface.

 

I/O modules Input-output interface, 

What is the primary function of an I/O module in a computer system?

a) To perform arithmetic and logical operations

b) To control the flow of data between the CPU and peripheral devices

c) To store and retrieve data from memory

d) To execute program instructions

Answer: b) To control the flow of data between the CPU and peripheral devices

Explanation: I/O modules facilitate communication between the CPU and peripheral devices by controlling the transfer of data, commands, and status information.

Which component of the I/O module is responsible for converting parallel data from the CPU into serial data for transmission over communication channels?

a) Input port

b) Output port

c) Buffer

d) Serial interface

Answer: d) Serial interface

Explanation: The serial interface within an I/O module converts parallel data from the CPU into serial data for transmission over communication channels, enabling efficient data transfer.

Which type of I/O module performs data transfer operations independently of the CPU, allowing the CPU to continue executing other instructions?

a) Programmed I/O

b) Interrupt-driven I/O

c) Direct memory access (DMA)

d) Memory-mapped I/O

Answer: c) Direct memory access (DMA)

Explanation: Direct memory access (DMA) allows peripheral devices to transfer data directly to and from memory without CPU intervention, freeing the CPU to perform other tasks.

What is the purpose of the input port in an I/O module?

a) To store data temporarily during data transfer operations

b) To receive incoming data from peripheral devices

c) To convert parallel data into serial data

d) To control the flow of data between the CPU and peripheral devices

Answer: b) To receive incoming data from peripheral devices

Explanation: The input port in an I/O module is responsible for receiving incoming data from peripheral devices and transferring it to the CPU or memory.

Which technique is commonly used to synchronize data transfer between the CPU and I/O modules?

a) Clock synchronization

b) Interrupt-driven synchronization

c) Handshaking

d) Buffering

Answer: c) Handshaking

Explanation: Handshaking is a technique used to synchronize data transfer between the CPU and I/O modules by exchanging control signals to indicate readiness for data transmission or reception.

Which component of the I/O module is responsible for temporarily storing data during data transfer operations?

a) Input port

b) Output port

c) Buffer

d) Serial interface

Answer: c) Buffer

Explanation: Buffers within an I/O module are used to temporarily store data during data transfer operations to compensate for differences in data transfer rates between devices.

Which type of I/O module requires the CPU to initiate and control each data transfer operation?

a) Programmed I/O

b) Interrupt-driven I/O

c) Direct memory access (DMA)

d) Memory-mapped I/O

Answer: a) Programmed I/O

Explanation: In programmed I/O, the CPU initiates and controls each data transfer operation by issuing commands to the I/O module, which then performs the requested operation.

What is the purpose of the output port in an I/O module?

a) To store data temporarily during data transfer operations

b) To receive incoming data from peripheral devices

c) To convert parallel data into serial data

d) To send outgoing data to peripheral devices

Answer: d) To send outgoing data to peripheral devices

Explanation: The output port in an I/O module is responsible for sending outgoing data from the CPU or memory to peripheral devices for processing or storage.

Which type of I/O module uses special hardware circuitry to generate interrupts to the CPU upon completion of data transfer operations?

a) Programmed I/O

b) Interrupt-driven I/O

c) Direct memory access (DMA)

d) Memory-mapped I/O

Answer: b) Interrupt-driven I/O

Explanation: Interrupt-driven I/O modules use special hardware circuitry to generate interrupts to the CPU upon completion of data transfer operations, allowing the CPU to respond promptly.

What is the purpose of memory-mapped I/O in the context of I/O modules?

a) To control the flow of data between the CPU and peripheral devices

b) To store data temporarily during data transfer operations

c) To map I/O device registers directly into the memory address space

d) To convert parallel data into serial data

Answer: c) To map I/O device registers directly into the memory address space

Explanation: Memory-mapped I/O allows I/O device registers to be mapped directly into the memory address space, enabling the CPU to access them using standard memory read and write instructions.

 

Modes of transfer Direct Memory access

 

What is the primary purpose of Direct Memory Access (DMA) in computer systems?

a) To perform arithmetic and logical operations

b) To control the flow of data between the CPU and peripheral devices

c) To allocate memory space for user applications

d) To synchronize processes in a multiprocessor system

Answer: b) To control the flow of data between the CPU and peripheral devices

Explanation: DMA is used to offload data transfer tasks between peripheral devices and memory, freeing the CPU from direct involvement in data transfer operations.

Which of the following statements best describes the operation of DMA?

a) DMA allows the CPU to perform data transfer operations directly between peripheral devices and memory.

b) DMA allows peripheral devices to transfer data directly to and from memory without CPU intervention.

c) DMA enables parallel processing of multiple tasks by multiple CPUs.

d) DMA facilitates communication between devices using a serial interface.

Answer: b) DMA allows peripheral devices to transfer data directly to and from memory without CPU intervention.

Explanation: DMA enables peripheral devices to transfer data directly to and from memory without CPU intervention, improving overall system performance.

In DMA operation, what role does the DMA controller play?

a) It controls the flow of data between the CPU and peripheral devices.

b) It converts parallel data into serial data for transmission over communication channels.

c) It manages the allocation of memory resources for user applications.

d) It coordinates and controls data transfer operations between peripheral devices and memory.

Answer: d) It coordinates and controls data transfer operations between peripheral devices and memory.

Explanation: The DMA controller manages and coordinates data transfer operations between peripheral devices and memory, including initiating transfers, managing addresses, and handling interrupts.

Which mode of DMA transfer allows the DMA controller to take control of the system bus and directly access memory without CPU intervention?

a) Burst mode

b) Cycle stealing mode

c) Block mode

d) Demand mode

Answer: b) Cycle stealing mode

Explanation: In cycle stealing mode, the DMA controller temporarily takes control of the system bus during data transfer operations, allowing direct access to memory without CPU intervention.

Which statement accurately describes burst mode DMA transfer?

a) Burst mode DMA transfers data continuously without interruption until the entire block of data is transferred.

b) Burst mode DMA transfers data in small, fixed-size bursts with pauses between bursts.

c) Burst mode DMA allows multiple devices to share the same DMA channel for simultaneous data transfer.

d) Burst mode DMA automatically adjusts the transfer rate based on the availability of system resources.

Answer: a) Burst mode DMA transfers data continuously without interruption until the entire block of data is transferred.

Explanation: Burst mode DMA transfers data continuously without interruption until the entire block of data is transferred, maximizing data transfer throughput.

In block mode DMA transfer, how is data transferred between the DMA controller and memory?

a) Data is transferred one byte at a time.

b) Data is transferred in fixed-size blocks.

c) Data is transferred continuously without interruption.

d) Data is transferred using a serial interface.

Answer: b) Data is transferred in fixed-size blocks.

Explanation: In block mode DMA transfer, data is transferred between the DMA controller and memory in fixed-size blocks, improving efficiency and reducing overhead.

What is the advantage of demand mode DMA transfer over cycle stealing mode?

a) Demand mode DMA allows for faster data transfer rates.

b) Demand mode DMA requires less memory bandwidth.

c) Demand mode DMA allows the CPU to access memory simultaneously with DMA transfers.

d) Demand mode DMA eliminates the need for DMA controllers.

Answer: c) Demand mode DMA allows the CPU to access memory simultaneously with DMA transfers.

Explanation: In demand mode DMA, the CPU can access memory simultaneously with DMA transfers, allowing for more efficient utilization of memory bandwidth.

Which DMA transfer mode is commonly used for transferring data between disk drives and memory in computer systems?

a) Burst mode

b) Cycle stealing mode

c) Block mode

d) Demand mode

Answer: c) Block mode

Explanation: Block mode DMA transfer is commonly used for transferring data between disk drives and memory in computer systems, allowing for efficient and reliable data transfer.

Which statement accurately describes scatter-gather DMA transfer?

a) Scatter-gather DMA transfers data between multiple peripheral devices and memory simultaneously.

b) Scatter-gather DMA transfers data in a continuous stream without interruption.

c) Scatter-gather DMA allows data to be transferred to and from non-contiguous memory locations in a single operation.

d) Scatter-gather DMA requires the use of dedicated DMA channels for each peripheral device.

Answer: c) Scatter-gather DMA allows data to be transferred to and from non-contiguous memory locations in a single operation.

Explanation: Scatter-gather DMA allows data to be transferred to and from non-contiguous memory locations in a single operation, reducing overhead and improving efficiency.

What is the primary benefit of using DMA for data transfer operations?

a) Reduced CPU overhead and improved system performance

b) Increased CPU utilization and faster data transfer rates

c) Simplified system architecture and lower cost

d) Improved compatibility with legacy peripheral devices

Answer: a) Reduced CPU overhead and improved system performance

Explanation: DMA offloads data transfer tasks from the CPU, reducing CPU overhead and allowing the CPU to focus on executing other tasks, leading to improved system performance.

 

Characteristics of multiprocessors

 

What is a key characteristic of multiprocessor systems?

a) They have a single processor unit.

b) They cannot execute multiple tasks simultaneously.

c) They consist of multiple processor units connected by a communication network.

d) They have limited memory capacity.

Answer: c) They consist of multiple processor units connected by a communication network.

Explanation: Multiprocessor systems consist of multiple processor units that share access to memory and peripheral devices through a communication network, enabling parallel execution of tasks.

Which term refers to the ability of multiprocessor systems to execute multiple tasks simultaneously?

a) Parallel processing

b) Serial processing

c) Sequential processing

d) Distributed processing

Answer: a) Parallel processing

Explanation: Multiprocessor systems leverage parallel processing, enabling multiple tasks to be executed simultaneously across multiple processor units.

What is a benefit of parallel processing in multiprocessor systems?

a) Increased complexity of system design

b) Reduced system reliability

c) Improved system performance and throughput

d) Higher cost of hardware maintenance

Answer: c) Improved system performance and throughput

Explanation: Parallel processing in multiprocessor systems leads to improved system performance and throughput by allowing tasks to be executed concurrently, reducing overall processing time.

Which type of multiprocessor architecture allows any processor to access any memory location?

a) Uniform Memory Access (UMA)

b) Non-Uniform Memory Access (NUMA)

c) Symmetric Multiprocessing (SMP)

d) Distributed Memory Architecture (DMA)

Answer: a) Uniform Memory Access (UMA)

Explanation: In Uniform Memory Access (UMA) architecture, any processor can access any memory location with uniform access time, simplifying memory management in multiprocessor systems.

Which characteristic distinguishes Symmetric Multiprocessing (SMP) from other multiprocessor architectures?

a) Asymmetric distribution of processing power

b) Non-uniform memory access latency

c) Shared memory space accessible by all processors

d) Distributed control of system resources

Answer: c) Shared memory space accessible by all processors

Explanation: Symmetric Multiprocessing (SMP) architectures feature a shared memory space accessible by all processors, allowing efficient communication and coordination between processors.

What is a disadvantage of Non-Uniform Memory Access (NUMA) architecture?

a) Higher memory access latency for all processors

b) Increased complexity of memory management

c) Limited scalability for large-scale systems

d) Inefficient utilization of system resources

Answer: a) Higher memory access latency for all processors

Explanation: In NUMA architecture, memory access latency can vary depending on the distance between processors and memory modules, leading to higher latency for some processors.

Which characteristic is a key advantage of Distributed Memory Architecture (DMA) in multiprocessor systems?

a) Shared memory space accessible by all processors

b) Low-latency memory access for all processors

c) Scalability for large-scale systems

d) Uniform memory access time

Answer: c) Scalability for large-scale systems

Explanation: Distributed Memory Architecture (DMA) provides scalability for large-scale systems by distributing memory across multiple memory modules, allowing for efficient expansion of memory capacity.

What does Cache Coherence refer to in multiprocessor systems?

a) The consistency of data stored in cache memory across multiple processors

b) The synchronization of clock cycles between processors

c) The distribution of processing tasks among multiple processors

d) The availability of redundant cache memory in case of failures

Answer: a) The consistency of data stored in cache memory across multiple processors

Explanation: Cache coherence ensures that data stored in cache memory across multiple processors remains consistent and up-to-date, preventing inconsistencies in shared data.

Which characteristic is associated with Scalability in multiprocessor systems?

a) Fixed number of processors

b) Limited memory capacity

c) Ability to add or remove processors dynamically

d) Homogeneous processor architecture

Answer: c) Ability to add or remove processors dynamically

Explanation: Scalability in multiprocessor systems refers to the ability to add or remove processors dynamically to meet changing workload demands, allowing for flexible system expansion.

What is the primary goal of Load Balancing in multiprocessor systems?

a) To overload individual processors with excessive tasks

b) To ensure uniform distribution of processing tasks among all processors

c) To limit the number of active processors to conserve energy

d) To prioritize certain tasks over others based on importance

Answer: b) To ensure uniform distribution of processing tasks among all processors

Explanation: Load balancing aims to evenly distribute processing tasks among all available processors in a multiprocessor system, ensuring efficient utilization of system resources and avoiding processor bottlenecks.

 

Interconnection Structure 

 

What is the purpose of the interconnection structure in multiprocessor systems?

a) To connect peripheral devices to the CPU

b) To enable communication between processors and memory

c) To manage power distribution within the system

d) To provide cooling for system components

Answer: b) To enable communication between processors and memory

Explanation: The interconnection structure facilitates communication between processors and memory, allowing data to be exchanged efficiently within the multiprocessor system.

Which type of interconnection structure allows each processor to have a direct connection to every other processor in the system?

a) Bus-based topology

b) Ring topology

c) Mesh topology

d) Crossbar switch

Answer: d) Crossbar switch

Explanation: A crossbar switch allows for a full mesh interconnection, where each processor has a direct connection to every other processor, enabling efficient communication between processors.

What is a characteristic of a bus-based interconnection structure?

a) Low scalability

b) High cost

c) Point-to-point connections

d) Centralized control

Answer: c) Point-to-point connections

Explanation: In a bus-based interconnection structure, point-to-point connections are established between processors and memory modules via a shared bus, allowing for communication between components.

Which topology consists of interconnected nodes arranged in a circular configuration?

a) Bus topology

b) Ring topology

c) Mesh topology

d) Star topology

Answer: b) Ring topology

Explanation: In a ring topology, each node is connected to two other nodes, forming a closed loop configuration, facilitating data transmission in a sequential manner.

What is a benefit of a mesh interconnection structure?

a) High fault tolerance

b) Low complexity

c) Centralized control

d) Limited scalability

Answer: a) High fault tolerance

Explanation: A mesh interconnection structure offers high fault tolerance because multiple paths are available for data transmission, allowing for rerouting in case of link failures.

Which type of interconnection structure features a centralized controller that manages data traffic between nodes?

a) Mesh topology

b) Star topology

c) Crossbar switch

d) Ring topology

Answer: b) Star topology

Explanation: In a star topology, all nodes are connected to a central controller or hub, which manages data traffic between nodes, providing a centralized control mechanism.

In a hypercube interconnection structure, how many links does each node have?

a) n - 1 links

b) n links

c) 2n links

d) 2n - 1 links

Answer: a) n - 1 links

Explanation: In a hypercube interconnection structure with n nodes, each node is connected to n - 1 other nodes, forming a hypercube network.

What is a drawback of a fully connected interconnection structure?

a) Low fault tolerance

b) Limited scalability

c) High complexity

d) Centralized control

Answer: c) High complexity

Explanation: A fully connected interconnection structure requires a large number of links and ports, resulting in high complexity and increased hardware cost.

Which type of interconnection structure provides the highest bandwidth and lowest latency?

a) Bus topology

b) Star topology

c) Crossbar switch

d) Ring topology

Answer: c) Crossbar switch

Explanation: A crossbar switch offers the highest bandwidth and lowest latency because it allows for simultaneous communication between any pair of nodes in the system.

What is a characteristic of a hierarchical interconnection structure?

a) It consists of a single centralized controller.

b) It allows for direct communication between any pair of nodes.

c) It organizes nodes into multiple layers with varying levels of connectivity.

d) It provides uniform bandwidth and latency across all connections.

Answer: c) It organizes nodes into multiple layers with varying levels of connectivity.

Explanation: A hierarchical interconnection structure organizes nodes into multiple layers with varying levels of connectivity, allowing for efficient communication within each layer and between layers.

 

Inter-processor Communication and synchronization

 

What is the primary purpose of inter-processor communication in multiprocessor systems?

a) To exchange data between processors and peripheral devices

b) To synchronize the execution of tasks across multiple processors

c) To manage power distribution within the system

d) To control the flow of data between the CPU and memory

Answer: b) To synchronize the execution of tasks across multiple processors

Explanation: Inter-processor communication allows processors in a multiprocessor system to synchronize their execution and exchange data as needed to perform parallel tasks efficiently.

Which mechanism is commonly used for inter-processor communication in tightly coupled multiprocessor systems?

a) Shared memory

b) Message passing

c) Bus arbitration

d) Interrupt handling

Answer: a) Shared memory

Explanation: Shared memory is a common mechanism for inter-processor communication in tightly coupled multiprocessor systems, where all processors have access to a shared memory space.

What is a characteristic of message passing for inter-processor communication?

a) It requires all processors to access a shared memory space.

b) It involves direct data exchange between processors using dedicated communication channels.

c) It relies on interrupts to coordinate communication between processors.

d) It allows processors to exchange data by sending and receiving messages through a communication network.

Answer: d) It allows processors to exchange data by sending and receiving messages through a communication network.

Explanation: In message passing, processors exchange data by sending and receiving messages through a communication network, enabling communication between processors without shared memory.

Which synchronization primitive is commonly used to coordinate access to shared resources among multiple processors?

a) Semaphore

b) Mutex

c) Barrier

d) Monitor

Answer: a) Semaphore

Explanation: Semaphores are commonly used synchronization primitives that control access to shared resources by allowing or blocking access based on resource availability.

What is the purpose of a barrier synchronization mechanism?

a) To prevent race conditions in shared memory access

b) To coordinate the execution of multiple processors at a specific point

c) To manage the allocation of memory resources for user applications

d) To synchronize clock cycles between processors

Answer: b) To coordinate the execution of multiple processors at a specific point

Explanation: Barrier synchronization mechanisms are used to coordinate the execution of multiple processors at specific points in a program, ensuring that all processors reach the same point before proceeding.

Which technique is commonly used for implementing mutual exclusion in multiprocessor systems?

a) Busy waiting

b) Spinlock

c) Priority inversion

d) Deadlock detection

Answer: b) Spinlock

Explanation: Spinlocks are commonly used to implement mutual exclusion in multiprocessor systems, where a processor "spins" in a loop while waiting for access to a shared resource.

What is a potential drawback of using busy waiting for synchronization in multiprocessor systems?

a) Increased system complexity

b) High processor utilization

c) Risk of priority inversion

d) Wasteful consumption of CPU resources

Answer: d) Wasteful consumption of CPU resources

Explanation: Busy waiting involves repeatedly checking a condition in a loop, which can lead to wasteful consumption of CPU resources if the condition is not immediately satisfied.

Which synchronization primitive allows multiple processes or threads to wait for each other at a predefined point?

a) Semaphore

b) Mutex

c) Barrier

d) Monitor

Answer: c) Barrier

Explanation: Barrier synchronization primitives allow multiple processes or threads to wait for each other at a predefined point in a program, ensuring that all participants reach the barrier before proceeding.

In a multiprocessor system, what is the purpose of a mutex?

a) To manage access to shared resources

b) To coordinate communication between processors

c) To synchronize clock cycles between processors

d) To prevent race conditions in shared memory access

Answer: a) To manage access to shared resources

Explanation: Mutexes are used to manage access to shared resources by allowing only one processor to access the resource at a time, thus preventing conflicts and race conditions.

What role does a monitor play in inter-processor communication and synchronization?

a) It provides a centralized control mechanism for managing communication channels between processors.

b) It coordinates the execution of multiple processors at specific points in a program.

c) It implements mutual exclusion and condition variables for synchronized access to shared resources.

d) It facilitates direct data exchange between processors using message passing.

Answer: c) It implements mutual exclusion and condition variables for synchronized access to shared resources.

Explanation: Monitors provide a high-level synchronization mechanism by implementing mutual exclusion and condition variables, allowing synchronized access to shared resources in a multiprocessor system.