RISC vs. CISC Architectures: A Comprehensive Guide for Computer Science Students

Question 1

Which of the following is a key characteristic of a RISC (Reduced Instruction Set Computer) architecture?

Accepted Answer

Emphasizes a small number of simple instructions

Answer

Emphasizes a large number of complex instructions

Answer

Relies heavily on microcode to decode instructions

Answer

Typically uses a register-register architecture

Question 2

Which of the following is NOT a typical feature of a CISC (Complex Instruction Set Computer) architecture?

Accepted Answer

Emphasis on simplicity and efficiency

Answer

Complex instructions that perform multiple operations

Answer

Microcode-based instruction decoding

Answer

Use of registers for data storage

Question 3

In a load-store architecture, which type of instruction is used to transfer data between memory and registers?

Accepted Answer

Load/store instructions

Answer

Arithmetic instructions

Answer

Logical instructions

Answer

Jump instructions

Question 4

True or False: CISC architectures are generally more difficult to implement than RISC architectures.

Accepted Answer

True

Answer

False

Question 5

What is the primary purpose of using microcode in CISC processors?

Accepted Answer

To decode complex instructions

Answer

To increase the number of registers

Answer

To improve memory access speed

Answer

To reduce the size of the instruction set

Question 6

For embedded systems, which architecture is typically more suitable?

Accepted Answer

RISC, due to its simplicity and efficiency.

Answer

CISC, due to its powerful instruction set.

Answer

Both RISC and CISC, depending on specific system requirements.

Answer

Neither RISC nor CISC, as they are not well-suited for embedded systems.

Question 7

Which of the following is NOT an advantage commonly associated with RISC architectures?

Accepted Answer

Enhanced instruction decoding complexity.

Answer

Higher clock speeds facilitated by simpler instructions.

Answer

Reduced code size resulting from a smaller instruction set.

Answer

Increased power efficiency due to streamlined instruction execution.

Question 8

When comparing RISC and CISC architectures, which one typically requires a smaller instruction cache?

Accepted Answer

RISC, due to its fixed-length instructions.

Answer

CISC, due to its variable-length instructions.

Answer

Both RISC and CISC, as they have similar cache requirements.

Answer

Neither RISC nor CISC, as cache size is determined by other factors.

Question 9

In the realm of practical applications, which of the following is an example of a widely used RISC processor?

Accepted Answer

ARM Cortex-A76, a popular RISC processor for mobile devices.

Answer

Intel Core i9, a high-performance CISC processor.

Answer

AMD Ryzen 9 5950X, a powerful CISC processor for desktop computers.

Answer

IBM z15, a mainframe processor with CISC architecture.

Question 10

Regarding instruction decoding, what is a key difference between RISC and CISC architectures?

Accepted Answer

RISC employs fixed-length instructions, while CISC utilizes variable-length instructions.

Answer

RISC relies on microinstructions, whereas CISC leverages macroinstructions.

Answer

RISC features a smaller instruction set compared to CISC.

Answer

RISC uses software decoding, unlike CISC which employs hardware decoding.

Question 11

Which of the following best describes a characteristic of CISC (Complex Instruction Set Computer) instructions?

Accepted Answer

They often execute multiple operations in a single instruction.

Answer

They typically perform a single operation.

Answer

They are always fixed in length.

Answer

They are encoded in a simple and straightforward manner.

Question 12

How has microprogramming influenced the evolution of CISC architectures?

Accepted Answer

Microprogramming provided flexibility and efficiency in implementing complex instructions, allowing customization for specific needs.

Answer

Microprogramming primarily enhanced the performance of CISC architectures by optimizing frequently used instructions.

Answer

Microprogramming simplified the design and implementation of CISC architectures by reducing hardware complexity.

Answer

Microprogramming had a negligible impact on the design and implementation of CISC architectures.

Question 13

Which of the following is a fundamental difference between RISC and CISC architectures in terms of instruction complexity?

Accepted Answer

CISC instructions are typically more complex than RISC instructions.

Answer

RISC instructions are generally more complex than CISC instructions.

Answer

Both RISC and CISC instructions have the same level of complexity.

Answer

The complexity of instructions is not a differentiating factor between RISC and CISC architectures.

Question 14

Which of the following is a primary design principle that differentiates RISC processors from CISC processors?

Accepted Answer

RISC processors emphasize simplicity and a reduced instruction set.

Answer

CISC processors prioritize a large instruction set and complex instructions.

Answer

Both RISC and CISC processors follow similar design principles.

Answer

RISC processors focus on instruction pipelining, while CISC processors do not.

Question 15

Which of the areas listed below is NOT typically an application domain for CISC architectures?

Accepted Answer

Embedded systems

Answer

Mainframes

Answer

Personal computers

Answer

Supercomputing

Question 16

What is the fundamental difference in addressing modes between RISC and CISC architectures?

Accepted Answer

RISC primarily uses register-based addressing, while CISC primarily uses memory-based addressing.

Answer

CISC primarily uses register-based addressing, while RISC primarily uses memory-based addressing.

Answer

RISC and CISC architectures use the same addressing modes.

Answer

The addressing mode is not a differentiating factor between RISC and CISC architectures.

Question 17

Which of the following aspects poses a challenge in designing RISC architectures?

Accepted Answer

Implementing complex instructions in software

Answer

Achieving high performance with simple instructions

Answer

Ensuring compatibility with existing software

Answer

Designing complex hardware circuits

Question 18

What is a primary advantage of utilizing a pipeline structure in RISC architectures?

Accepted Answer

Improved instruction execution speed

Answer

Reduced power consumption

Answer

Simplified instruction decoding

Answer

Enhanced code compatibility

Question 19

CISC processors are characterized by:

Accepted Answer

Instructions that can perform multiple operations, reducing memory access

Answer

A streamlined instruction set designed for faster execution

Answer

Heavy utilization of pipelining to improve performance

Question 20

A notable architectural feature of RISC processors is:

Accepted Answer

The use of a load/store architecture, separating data access from processing

Answer

Incorporating multiple execution units for parallel processing

Answer

Inherent support for floating-point operations within the instruction set

Answer

Extensive reliance on microprogramming for instruction decoding

Question 21

A key difference between RISC and CISC instructions is that:

Accepted Answer

RISC instructions are typically shorter and fixed-length, while CISC instructions vary in length

Answer

RISC instructions offer a broader range of addressing modes

Answer

CISC instructions can directly access memory operands

Question 22

One advantage of utilizing a microprogrammed control unit in CISC processors is:

Accepted Answer

Greater flexibility in implementing new instructions and enhancing the instruction set

Answer

Reduced need for external memory, leading to a smaller overall system size

Answer

Improved instruction cache performance due to optimized instruction fetching

Question 23

In a RISC architecture, the primary function of registers is to:

Accepted Answer

Store operands and results during instruction execution

Answer

Decode instructions and perform memory addressing

Answer

Temporarily hold data awaiting transfer to memory

Answer

Control the flow of execution by managing program counter and condition codes

Question 24

Which of the following is NOT a typical characteristic of a CISC processor?

Accepted Answer

Simple, single-cycle instruction execution

Answer

Variable-length instructions, accommodating complex operations

Answer

Support for multiple addressing modes, providing flexibility

Answer

Extensive use of microcode to implement complex instructions