Final Test: Computer Architecture

The grade formula is as follows:

Grade = 0.4 * Theory + 0.6 * Programming

Part 1. Theoretical Questions

Please submit your answers using this form.

Answer the theoretical questions in a few sentences (1-2 sentences for a question).

Use your own words. Copy-paste from external sources and other students will result in 100% penalty.

Assessment criteria:

• Answers to each of the question three topics (data formats, CPU, memory) have the same weight and can give up to 3.33 points each.
• Answers to subquestions are evaluated as a whole (they are numbered in order not to be missed). Generally, the most basic questions come first.

Questions:

• Data formats.
  1. Describe how integers are represented in the binary format (unsigned integers, 2’s complement).
  2. What is the difference between integer sign- and zero-extension?
  3. What is the difference between arithmetical and logical shift?
  4. What is integer overflow?
  5. Explain the floating-point format (sign, exponent, fraction). Describe single and double precision.
  6. What is implicit 1. in fraction?
  7. Why exponents are biased and what is bias?
  8. What are floating-point overflow and underflow?
• CPU.
  1. Describe the concept of pipeline. List the 5 pipeline stages with brief descriptions.
  2. What pipeline hazards are? List hazards and ways to prevent them.
  3. Give an example of a hazard situation and how it can be handled.
  4. Explain what branch prediction is needed for.
  5. Explain the idea of multiple-issue (superscalar) processor and out-of-order execution.
  6. List the types of thread-level parallelism with brief explanation.
  7. How the loop unrolling optimization can help improve performance?
  8. What CPU does your laptop/desktop have (model name)? How many cores does it have?
• Memory.
  1. Describe the idea of memory hierarchy. Why do we need it?
  2. Explain what a cache is and how it works (block, index, tag, valid bit, dirty bit).
  3. Give the definition of associativity (direct-mapped, set associative, fully associative).
  4. What is the difference between write-through and write-back?
  5. What is replacement policy (what types of policy do you know)?
  6. Explain how CPU translates virtual addresses into physical.
  7. What is a TLB miss and what is a page fault?
  8. How many caches does your laptop/desktop have?

Part 2. Programming Task

Write a RISC-V assembly program that implements function f(x) according to the specified formula (individual for each of the students). The task is split into 7 subtasks (steps). This is done to be able to evaluate incomplete solutions.

Assessment criteria:

1. Tasks 1-4 (full solution) give 1 points each.
2. Tasks 5-7 (full solution) give 2 points each.
3. Full solution of all tasks gives 10 points.

Ejudge contests by groups:

• Group 231
• Group 232
• Group 233
• Group 234