set-8

Answer: 1. Magnetic core memory

Explanation:

• Magnetic core memory was one of the earliest forms of non-volatile memory. It used tiny magnetic cores to store data and was widely used in early computers before the advent of semiconductor memory.

Answer: 1. SRAM

Explanation:

• SRAM (Static Random Access Memory) is faster than DRAM (Dynamic Random Access Memory) because it does not require periodic refreshing. SRAM is used in cache memory due to its high speed.

Answer: 1. DRAM

Explanation:

• In DRAM, the address signals are multiplexed to reduce the number of pins required. This means that the row and column addresses are sent over the same set of pins at different times.

Answer: 2. 4

Explanation:

• The main signals used with memory chips are typically 4:
  1. Address Bus (to specify the memory location).
  2. Data Bus (to transfer data).
  3. Read/Write Signal (to control read/write operations).
  4. Chip Select Signal (to enable the memory chip).

Answer: 3. To select a location within the memory chip

Explanation:

• The address bus is used to specify the memory location within the memory chip that needs to be accessed for reading or writing data.

Answer: 1. Sockets and slots

Explanation:

• Processors are connected to the motherboard using either sockets (for CPUs that are inserted into a socket) or slots (for CPUs that are inserted into a slot, such as older Intel Pentium II/III processors).

Answer: 4. FPGA

Explanation:

• FPGA (Field-Programmable Gate Array) is a type of programmable hardware that can be configured to perform specific tasks after manufacturing. It is widely used in prototyping and custom hardware design.

Answer: 4. NXP Semiconductor

Explanation:

• The TriMedia processor was developed by NXP Semiconductor (formerly Philips Semiconductors). It is designed for multimedia applications and digital signal processing.

Answer: 2. M68000

Explanation:

• The Motorola 68000 (M68000) processor has a 24-bit address bus, allowing it to address up to 16 MB of memory.

Answer: 1. Delays can cause timing errors in real-time systems.

Explanation:

• In real-time systems, delays can lead to timing errors, causing the system to miss deadlines or produce incorrect results. This is especially critical in systems where timing is crucial, such as control systems or signal processing.

Answer: 3. 3

Explanation:

• There are three main ways to allocate memory to modular blocks:
  1. Static Allocation: Memory is allocated at compile time.
  2. Stack Allocation: Memory is allocated dynamically during runtime using a stack.
  3. Heap Allocation: Memory is allocated dynamically during runtime using a heap.

Answer: 1. Relative addressing mode

Explanation:

• Relative addressing mode is often replaced with absolute addressing mode when the exact memory location is known. Absolute addressing directly specifies the memory address, while relative addressing uses an offset from a base address.

Answer: 1. Address translation

Explanation:

• The Memory Management Unit (MMU) is responsible for address translation, converting virtual addresses used by programs into physical addresses used by the memory system. This enables features like virtual memory and memory protection.

Answer: 4. Memory partitioning

Explanation:

• Memory partitioning provides stability to multitasking systems by dividing memory into separate sections for different tasks. This prevents tasks from interfering with each other and ensures efficient memory usage.

Answer: 1. M68000

Explanation:

• The M68000 family refers to the Motorola 68000 series of processors, which were widely used in early personal computers and workstations.

Answer: 1. Add extra description bit

Explanation:

• Fine-grain protection can be achieved by adding extra description bits to memory addresses. These bits can specify access permissions (e.g., read-only, execute-only) for specific memory regions, enhancing security and stability.

Answer: 3. Virtual memory technique

Explanation:

• The UNIX operating system uses the virtual memory technique to manage memory. This allows processes to use more memory than physically available by swapping data between RAM and disk storage.

Answer: 4. Dual in-line

Explanation:

• Dual in-line refers to components (e.g., memory modules) that have two parallel rows of pins or legs on both sides of a plastic or ceramic body. Examples include DIP (Dual In-line Package) chips.

Answer: 4. Parallel port

Explanation:

• A parallel port can transfer multiple bits of data simultaneously over multiple wires. This makes it faster than a serial port, which transfers data one bit at a time.

Answer: 2. Switch

Explanation:

• Switches are commonly interfaced as inputs to parallel ports. They provide binary input (on/off) to the system, which can be read by the CPU.

Answer: 3. LEDs

Explanation:

• LEDs are commonly interfaced as outputs to parallel ports. They can be controlled by the CPU to indicate status or provide visual feedback.

Answer: 3. 2

Explanation:

• In the basic form, a parallel port is controlled by two registers:
  1. Data Register: Holds the data to be sent or received.
  2. Control Register: Manages the control signals for the port.

Answer: 1. Output port

Explanation:

• An output port is often referred to as tri-state because it can be in one of three states: high (1), low (0), or high-impedance (disconnected). This allows multiple devices to share a common bus without interference.

Answer: 2. By data direction register

Explanation:

• Buffers in parallel ports are enabled by the data direction register. This register determines whether each pin on the port is configured as an input or output.

Answer: 3. Individual control bit

Explanation:

• The individual control bit in a parallel port can be used to set a pin to high impedance (disconnected) state, allowing it to act as an open circuit.

Answer: 1. Multifunction I/O port

Explanation:

• A multifunction I/O port can be used as a chip select signal to enable or disable a specific chip in a system. This is commonly used in memory and peripheral interfacing.

Answer: 2. Pull-up resistor

Explanation:

• Pull-up resistors are necessary for parallel input-output ports to ensure that the input pins have a defined logic level (high or low) when no external signal is applied. This prevents floating inputs.

Answer: 1. Multifunction I/O port

Explanation:

• A multifunction I/O port is general-purpose because it can be configured to perform various functions, such as input, output, or bidirectional communication, depending on the system’s requirements.

Answer: 1. Universal asynchronous receiver transmitter

Explanation:

• UART stands for Universal Asynchronous Receiver Transmitter. It is a hardware device used for serial communication, converting parallel data from the CPU into serial data for transmission and vice versa.

Answer: 3. Clock

Explanation:

• In a UART, data is detected using a clock signal. The receiver synchronizes with the transmitter’s clock to sample the incoming data bits at the correct time.

Answer: 4. TXD

Explanation:

• The TXD (Transmit Data) signal is set to 1 (high) when no data is being transmitted. This is known as the idle state in UART communication.

Answer: 2. Baud rate

Explanation:

• The baud rate defines the timing in UART communication. It specifies the number of signal changes (symbols) per second and determines the speed of data transmission.

Answer: 2. External timer

Explanation:

• The baud rate is typically supplied by an external timer or oscillator. This ensures accurate timing for data transmission and reception in UART communication.

Answer: 4. 8250

Explanation:

• The 8250 UART is the most commonly used UART chip. It is widely used in PCs and embedded systems for serial communication.

Answer: 3. National semiconductor

Explanation:

• The 16450 UART was developed by National Semiconductor. It is an improved version of the 8250 UART, offering higher performance and additional features.

Answer: 3. Address strobe signal

Explanation:

• In the 8250 UART, ADS (Address Strobe Signal) is used to indicate that a valid address is present on the address bus. It is used to latch the address for further processing.

Answer: 1. BAUDOUT

Explanation:

• In the 8250 UART, the BAUDOUT signal is active low. It is used to output the baud rate clock for external synchronization.

Answer: 2. DDIS

Explanation:

• The DDIS (Driver Disable) signal in the 8250 UART can control bus arbitration logic. It is used to disable the data bus drivers when the CPU is not accessing the UART.

Answer: 4. RS232

Explanation:

• RS232 is a serial communication standard that can be used for long-distance communication. It is commonly used for connecting computers to modems and other peripheral devices.

Answer: 1. Clock

Explanation:

• The clock signal is critical in long-distance communication because it synchronizes data transmission between devices. Any issues with the clock signal (e.g., jitter or skew) can affect communication reliability.

Answer: 3. COM1 and COM2

Explanation:

• The IBM PC typically has two serial ports: COM1 and COM2. These ports are used for serial communication with devices like modems and mice.

Answer: 1. RS232

Explanation:

• RS232 supports hardware handshaking using signals like RTS (Request to Send) and CTS (Clear to Send). This ensures reliable data transfer by controlling the flow of data between devices.

Answer: 2. RS232

Explanation:

• RS232 uses asynchronous data transmission, where data is sent without a shared clock signal. Instead, start and stop bits are used to synchronize the transmission.

Answer: 3. 2

Explanation:

• The serial interface typically has two areas:
  1. Data transmission area: Handles the actual data transfer.
  2. Control area: Manages handshaking and flow control.

Answer: 4. Electrical interface

Explanation:

• RS232 is primarily an electrical interface standard that defines the voltage levels, signal timing, and connector types for serial communication.

Answer: 2. 5V

Explanation:

• The MC1489 is a line receiver IC that operates at 5V. It is commonly used in RS232 communication to convert RS232 voltage levels to TTL levels.

Answer: 3. Serial port

Explanation:

• A serial port is a physical interface, not a protocol. Protocols like SPI, I2C, and RS232 define the rules for data transmission over a serial connection.

Answer: 1. SPI

Explanation:

• SPI (Serial Peripheral Interface) is an ideal interface for LCD controllers because it provides high-speed, synchronous communication with minimal wiring.

Answer: 2. Multitask operating system

Explanation:

• A multitask operating system divides the processor’s time among multiple tasks or processes. This allows multiple applications to run concurrently, improving system efficiency.

Answer: 3. Kernel

Explanation:

• The kernel of an operating system is responsible for task scheduling. It decides which task gets the next time slot based on priority, fairness, and other scheduling algorithms.