Quiz: Microprocessor Systems Architecture — 32 questions

1. What does computer science combine in its study of information processing?

A. Software with physical storage

B. Programming with network security

C. Information with automation

D. Hardware with electrical power

Answer: (C)

Explanation

Computer science studies the processing of information while combining information with automation. Hardware with electrical power describes a physical concern rather than the defining scope of computer science.

2. Which statement correctly distinguishes hardware from software?

A. Hardware is physical equipment, whereas software is a set of instructions that directs hardware.

B. Hardware stores instructions, whereas software supplies the electrical signals that power components.

C. Hardware and software are both physical components that differ mainly in their operating speeds.

D. Hardware interprets programs, whereas software consists of the computer's physical components.

Answer: (A)

Explanation

Hardware refers to the concrete physical parts of a computer, while software consists of stored instructions that define hardware actions. The second option reverses these roles by assigning instruction storage to hardware and physical operation to software.

3. What is the primary role of a microprocessor in a computer system?

A. It converts decimal numbers into binary representations.

B. It interprets and executes program instructions.

C. It connects peripheral devices through communication cables.

D. It preserves programs and data for later retrieval.

Answer: (B)

Explanation

A microprocessor is an integrated circuit that combines logic and interprets and executes program instructions. Preserving programs and data is a memory function, so that description confuses the processor with memory.

4. Which description of Intel's 4004 is historically accurate?

A. It was a 4-bit processor introduced in 1965 and operated at 10 kHz.

B. It was a 16-bit processor introduced in 1947 and operated at 108 MHz.

C. It was a 4-bit microprocessor introduced in 1971 and operated at 108 kHz.

D. It was an 8-bit microprocessor introduced in 1958 and operated at 1 MHz.

Answer: (C)

Explanation

Intel created the first microprocessor, the 4-bit 4004, in 1971, and it operated at 108 kHz. The alternative descriptions alter its bit size, date, or clock frequency and therefore do not match the historical facts.

5. Which statement best defines a bit?

A. A bit is a group of eight binary units used to store a character.

B. A bit is a decimal place whose value depends on its position.

C. A bit is a binary information unit that can hold 0 or 1.

D. A bit is a hexadecimal symbol selected from sixteen possible symbols.

Answer: (C)

Explanation

A bit is the elementary unit of binary information and has one of two values: 0 or 1. A group of eight bits is a byte, so that description applies to a different unit.

6. How many bits make up one byte?

A. Eight bits

B. Four bits

C. Two bits

D. Sixteen bits

Answer: (A)

Explanation

A byte is defined as a word made up of eight bits. Two possible bit values describe the range of a single bit, while sixteen refers to the number of symbols in hexadecimal notation.

7. What decimal value does the binary number $(101)_2$ represent?

A. $5$

B. $7$

C. $4$

D. $6$

Answer: (A)

Explanation

The binary number equals $1\times2^2+0\times2^1+1\times2^0=4+0+1=5$. The value $4$ would omit the contribution of the final binary digit, while the other values do not match the positional sum.

8. What decimal value does the hexadecimal number $(9A)_{16}$ represent?

A. $109$

B. $154$

C. $160$

D. $145$

Answer: (B)

Explanation

In hexadecimal, A represents 10, so $9\times16^1+10\times16^0=144+10=154$. The nearby values result from misreading A or using an incorrect positional calculation.

9. What is the von Neumann model?

A. A numerical system for representing data with sixteen symbols introduced by Intel in 1971.

B. A circuit design for storing binary values developed with the first transistor in 1947.

C. A programming language model for coordinating peripheral devices through software.

D. A universal architecture for programmed information processing proposed by John von Neumann in 1946.

Answer: (D)

Explanation

The von Neumann model is a universal machine architecture for programmed information processing, proposed by John von Neumann in 1946. The hexadecimal system and Intel's 4004 are separate computing concepts, while the remaining choice describes neither the model nor its historical origin.

10. Which components form a basic von Neumann system?

A. A central processing unit, main memory, and input/output interfaces linked by buses.

B. Main memory, a compiler, and a printer connected by storage channels.

C. A processor, a display, and a keyboard linked through wireless signals.

D. An arithmetic unit, a power supply, and a monitor joined by control software.

Answer: (A)

Explanation

A basic von Neumann system contains a central processing unit, main memory, and input/output interfaces connected by communication buses. A display and keyboard are peripherals that may use the interfaces, but they do not constitute the architecture's three basic components.

11. During instruction processing, which sequence best describes the microprocessor's role?

A. It receives input from peripherals, transfers it directly to output, and leaves instruction execution to memory.

B. It interprets and executes instructions, exchanges results with memory and peripherals, and follows the clock timing.

C. It calculates results in isolation, sends them to storage, and operates independently of communication units.

D. It stores every instruction permanently, converts all data to hexadecimal, and controls devices without clock timing.

Answer: (B)

Explanation

The microprocessor interprets and executes instructions, reads or saves results in memory, communicates with exchange units, and operates according to clock timing. Memory stores programs and data but does not replace the processor's instruction-execution role.

12. What is the primary function of a bus in a computer system?

A. It determines the execution order of processor instructions

B. It converts digital signals into analog electrical waves

C. It transmits the same type of information between components

D. It permanently stores instructions inside connected components

Answer: (C)

Explanation

A bus is a group of wires designed to transmit one type of information between system components. A bus does not itself serve as permanent storage or determine instruction sequencing.

13. Which bus carries information in both directions between a microprocessor and its environment?

A. The expansion bus

B. The data bus

C. The control bus

D. The address bus

Answer: (B)

Explanation

The data bus is bidirectional because information can move from the processor to other components and back. The address bus instead sends location selections in one direction.

14. Why does address decoding assign separate address zones to peripherals?

A. To allow every peripheral to transmit simultaneously on the data bus

B. To convert each peripheral's data into a different word format

C. To increase the number of conductors in the address bus

D. To select one component at a time and prevent shared-bus conflicts

Answer: (D)

Explanation

Address decoding maps peripherals to address zones so that only the intended component responds at a given time. Simultaneous responses would create conflicts on the shared data bus.

15. Which operation retrieves information that has previously been stored in memory?

A. Chip selection

B. Reading

C. Writing

D. Address decoding

Answer: (B)

Explanation

Reading retrieves stored information from memory, while writing places new information into a memory location. Address decoding and chip selection identify hardware rather than retrieve data.

16. Which sequence correctly describes a memory read or write cycle?

A. Select the memory, transfer the data, choose the operation, then select the address

B. Select the address, choose the operation, select the memory, then transfer the data

C. Choose the operation, transfer the data, select the address, then select the memory

D. Transfer the data, select the address, select the memory, then choose the operation

Answer: (B)

Explanation

A memory cycle first identifies the address, specifies reading or writing, selects the memory circuit, and then transfers the data. Reordering these stages does not match the defined cycle process.

17. What does memory capacity measure?

A. The time required to complete a memory cycle

B. The number of bits contained in one data word

C. The total number of bits stored in the memory

D. The number of addresses searched before access

Answer: (C)

Explanation

Memory capacity describes the total amount of information stored and is commonly expressed in bytes. The size of one word describes data format rather than total storage.

18. What interval is measured by memory access time?

A. From address generation until the memory loses stored information

B. From chip selection until all data words have been transferred

C. From the start of a read or write operation until the first data appears

D. From the end of one operation until the next operation begins

Answer: (C)

Explanation

Access time is the interval from launching a read or write operation to the availability of the first information on the data bus. The interval separating successive operations is cycle time instead.

19. A system must retrieve data from a known address in roughly the same time regardless of its location. Which access method fits this requirement?

A. Stream access

B. Random access

C. Sequential access

D. Serial access

Answer: (B)

Explanation

Random access reaches a known address in an address-independent time. Sequential access must pass through preceding information, so its access time depends on position.

20. What happens to information in volatile memory when electrical power fails?

A. The stored information becomes permanently read-only

B. The stored information is preserved unchanged

C. The stored information is lost or altered

D. The stored information moves to a neighboring address

Answer: (C)

Explanation

Volatility concerns the effect of power loss, and volatile memory loses or alters its stored information without electrical power. Non-volatile memory is the type that preserves information during power failure.

21. Which statement correctly contrasts RAM with ROM?

A. RAM generally stores temporary data and loses it when power is removed, whereas ROM retains non-volatile data.

B. RAM and ROM both retain their contents without power, but RAM provides faster access than ROM.

C. RAM stores permanent firmware and retains it without power, whereas ROM stores temporary working data.

D. RAM and ROM both lose their contents without power, but ROM provides greater capacity than RAM.

Answer: (A)

Explanation

RAM is generally volatile and supports temporary storage, while ROM provides permanent non-volatile storage. The claim that RAM stores permanent firmware reverses the usual distinction between the two technologies.

22. How does a DRAM cell store one bit compared with an SRAM cell?

A. DRAM stores the bit in a bistable transistor circuit, whereas SRAM stores it in a capacitor.

B. DRAM stores the bit in a magnetic domain, whereas SRAM stores it as charge in a capacitor.

C. DRAM stores the bit as charge in a capacitor, whereas SRAM stores it in a bistable transistor circuit.

D. DRAM stores the bit as a programmed fuse, whereas SRAM stores it in a bistable transistor circuit.

Answer: (C)

Explanation

A DRAM bit is represented by electrical charge in a capacitor, while an SRAM bit is held by a bistable circuit containing several transistors. The reversed pairing confuses the storage mechanisms of the two memory types.

23. Why must a DRAM cell be refreshed regularly during operation?

A. Ultraviolet exposure removes its charge, and each write requires the value to be restored.

B. Leakage currents gradually discharge its capacitor, and a destructive read requires the value to be rewritten.

C. Its bistable circuit loses one of two stable states, and reads must restore the missing transistor.

D. Clock edges erase its transistor state, and every read requires the cell to be reprogrammed.

Answer: (B)

Explanation

Leakage drains the capacitor charge in DRAM, and reading the cell destructively requires a subsequent rewrite. The clock-based explanation describes neither the physical cause of leakage nor the reason for rewriting after a read.

24. Why is DRAM commonly selected for main memory while SRAM is used for caches and registers?

A. DRAM provides higher speed and lower density, while SRAM offers lower cost in large memory arrays.

B. DRAM avoids refresh operations, while SRAM requires periodic capacitor charging in each cell.

C. DRAM is suited to register-sized arrays, while SRAM is selected for high-capacity main memory.

D. DRAM provides greater density and lower cost per bit, while SRAM offers higher speed in small memory arrays.

Answer: (D)

Explanation

DRAM is economical and dense enough for large main-memory systems, whereas faster SRAM is practical for smaller caches and registers. The distractor claiming that SRAM is cheaper for large arrays reverses the cost and size trade-off.

25. Who normally programs ROM, and how does PROM differ from it?

A. The manufacturer programs ROM, whereas the user can program PROM once.

B. The user programs ROM repeatedly, whereas the manufacturer programs PROM during fabrication.

C. The user programs both ROM and PROM, but ROM can be rewritten after installation.

D. The manufacturer programs both ROM and PROM, but PROM can be erased with ultraviolet light.

Answer: (A)

Explanation

Standard ROM is programmed by the manufacturer, while PROM is supplied programmable and can be programmed once by the user. The idea that the user can repeatedly program ROM confuses it with rewritable programmable memories.

26. Which method erases an EPROM so that it can be programmed again?

A. Exposure to ultraviolet radiation

B. Application of an electrical erase command

C. Removal of the memory from its address bus

D. Rewriting each word with a new binary pattern

Answer: (A)

Explanation

EPROM is erased by ultraviolet radiation and can then be reprogrammed many times. Electrical erasure is the characteristic associated with EEPROM rather than EPROM.

27. What capability distinguishes EEPROM from other programmable ROM technologies?

A. It is programmed by the manufacturer and cannot be changed by the user.

B. It is erased by ultraviolet radiation before being programmed again.

C. It can be programmed in place and erased electrically on a word-by-word basis.

D. It provides sequential sector access and byte-level programming.

Answer: (C)

Explanation

EEPROM supports in-circuit programming and electrical erasure of individual words. Ultraviolet erasure identifies EPROM, while sequential sector access describes a Flash NAND characteristic.

28. Which pairing correctly distinguishes Flash NOR from Flash NAND?

A. NOR and NAND both use random access, but NOR is erased ultravioletly while NAND is erased electrically.

B. NOR uses sequential access and sector-based programming, whereas NAND supports random access and byte-by-byte programming.

C. NOR and NAND both use sequential access, but NAND programs individual bytes while NOR programs sectors.

D. NOR supports random access and byte-by-byte programming, whereas NAND uses sequential access and sector-based programming.

Answer: (D)

Explanation

Flash NOR permits random access with byte-level programming, whereas Flash NAND is organized for sequential access and sector-based programming. The reversed access and programming characteristics are the central misconception in this comparison.

29. Which set contains the main criteria used when selecting a memory technology?

A. Clock frequency, instruction set, keyboard layout, and network protocol

B. Address width, operating system, display size, and file format

C. Capacity, speed, power consumption, and cost

D. Voltage, physical color, manufacturer, and connector shape

Answer: (C)

Explanation

Memory selection weighs capacity, speed, power consumption, and cost because these factors determine suitability for a system role. The other sets contain hardware or software characteristics that are not the stated primary selection criteria.

30. How does a memory hierarchy balance performance against cost?

A. It places frequently used information in large, slow memories and less-used information in small, fast memories.

B. It stores all information in the fastest memory to avoid differences in access time.

C. It keeps frequently used information in small, fast memories and less-used information in larger, slower memories.

D. It uses memories of equal size and speed so that every access has the same cost.

Answer: (C)

Explanation

The hierarchy improves performance by keeping active data close to the processor in small, fast memories while using larger, slower memories for less-used data. Reversing these placements would increase access time for the information used most often.

31. What is the typical order of memory hierarchy from the processor outward?

A. Mass storage, backing memory, main memory, cache memory, and registers

B. Registers, main memory, cache memory, mass storage, and backing memory

C. Registers, cache memory, main memory, backing memory, and mass storage

D. Cache memory, registers, backing memory, main memory, and mass storage

Answer: (C)

Explanation

The hierarchy proceeds outward from registers to cache, main memory, backing memory, and mass storage, with capacity generally increasing and access time becoming longer. Starting with mass storage reverses the processor-to-storage organization and its performance trend.

32. How does cache memory accelerate access to main memory?

A. It stores every program permanently on a large peripheral device for later retrieval.

B. It replaces main memory with a slower, higher-capacity storage medium.

C. It increases the capacity of mass storage by compressing infrequently used files.

D. It keeps frequently used data in a small, fast memory located closer to the processor.

Answer: (D)

Explanation

Cache is a small, fast memory that holds frequently accessed data so the processor can retrieve it more quickly than from main memory. Permanent storage on a large peripheral device describes mass storage rather than cache.