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J277 1.1 Systems architecture consolidation
Part 6 of 6 · J277 1.1 · Systems architecture
The end-of-topic checkpoint for OCR J277 section 1.1, mixing recall with an applied scenario and an extended answer.
Students will:
- recall CPU purpose, components and performance factors without support
- apply Von Neumann architecture and the four required registers
- explain the fetch-execute cycle in an unfamiliar context
- choose a processor for a scenario and justify the choice
- write an extended answer that develops several linked points
Inside: 4 explanation cells, 1 multiple-choice question, 2 fill-in-the-blanks cells and 8 written answers. 61 marks, about 75 minutes.
Series: J277 1.1 · Systems architecture, part 6 of 6.
Shared by Coding PathwayVerified teacher
- 15 cells
- About 75 minutes
- CC BY-SA 4.0
- Shared 17 Aug 2026
- Updated 9 Sept 2026
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The whole resource, exactly as a class sees it. Answers and marking are held back.
Systems architecture 6: consolidation and application
This worksheet brings together the whole of OCR J277 section 1.1:
- CPU purpose and components
- clock speed, cache size and number of cores
- Von Neumann architecture and the four required registers
- the fetch-execute cycle
- embedded systems
You are not expected to recall everything perfectly on the first attempt. Use the early questions to find what you know securely and what needs another look. Later questions give you less help and ask you to compare and apply your knowledge.
- decode
- cache
- secondary storage
- control unit
- router
- registers
- logical operations
- arithmetic logic unit
- Memory Address Register
- Program Counter
- Memory Data Register
- cache
- data
- control unit
- address
- accumulator
Which five statements are accurate? Select all that apply.
- AThe PC stores the address of the next instruction to be fetched
- BThe accumulator performs calculations instead of the ALU
- CThe ALU performs arithmetic calculations and logical operations
- DDoubling clock speed guarantees every program will finish in exactly half the time
- EA larger cache can hold more frequently used data and instructions
- FMore cores may provide little benefit if software cannot use parallel processing
- GOCR requires every register transfer in the fetch stage to be memorised in exact order
- HAn embedded-system answer should identify a dedicated function in its larger system
Describe the function of the control unit, ALU, cache and registers.
Write one precise point for each component. Avoid merely repeating the component name.
Students type their answer here.
Describe what happens during the fetch-execute cycle.
Give a concise overview using fetch, decode and execute. Relevant components or registers can add precision, but an exact register-transfer sequence is not required.
Students type their answer here.
State the three CPU characteristics named in OCR J277 that can affect performance.
Use each full characteristic name. Single words such as 'clock', 'cache' or 'cores' are too vague.
Students type their answer here.
Applied scenario: choosing a processor
A design studio is comparing two processors for software that can render several parts of an animation at the same time.
| Processor | Clock speed | Cache size | Cores |
|---|---|---|---|
| X | 4.2 GHz | 8 MB | 4 |
| Y | 3.6 GHz | 24 MB | 12 |
Read all three characteristics. The task can use several cores, but Processor X has the higher clock speed.
Recommend processor X or Y for the design studio. Justify your choice using all three CPU performance characteristics.
State the choice first. For each characteristic, quote the comparison, explain how it affects performance and apply it to rendering. Include one drawback or limitation. More than one choice can be defended if the reasoning is accurate.
Students type their answer here.
During processing, the next instruction is stored at memory address 350. The instruction is transferred to the CPU and an ALU operation produces the value 42.
Identify the register associated with each of these values and state what it stores:
A. The address of the next instruction
B. The address currently being accessed
C. The transferred instruction
D. The result 42
Write four register-purpose pairs. Distinguish the two addresses, the transferred instruction and the calculation result.
Students type their answer here.
A bridge contains a controller that monitors vibration sensors and activates warning signs when readings exceed safe limits. Explain three reasons why the controller is an embedded system.
Give three concise reasons and apply each one to the bridge controller.
Students type their answer here.
Final challenge: bring the ideas together
The bridge uses an embedded control computer, sometimes called a controller. It still contains a CPU. The CPU processes its program instructions through the fetch-execute cycle. The ALU can compare sensor readings with a safety limit, while the control unit coordinates the processing and the warning signs.
A strong answer can connect different levels of explanation:
device purpose → instruction being processed → CPU component action → result in the situation
The final challenge asks you to make those connections independently.
Challenge: bring performance and embedded systems together. The local council is considering a new embedded control computer for the bridge. It would have a higher clock speed, a larger cache and four cores instead of two. Evaluate how these changes could affect the system. Decide whether choosing the processor with the biggest numbers is necessarily the best choice.
Build a balanced response. Explain how clock speed, cache size and number of cores can affect performance. Link each point to monitoring sensors and controlling warning signs. Remember that the program may not be able to make full use of every core. Finish with a supported decision.
Students type their answer here.
Final closed-book retrieval: Write ten precise facts about systems architecture. Include at least two CPU components, two registers, two fetch-execute stages, two performance characteristics and two embedded-system characteristics.
Each category is worth 2 marks. Use full terms and a precise verb in every fact. Do not look back until you have written all ten.
Students type their answer here.
Self-check
After completing the final retrieval, check each statement against these questions:
- Did I name the exact component, register or characteristic?
- Did I say what it stores, manages or performs?
- Did I distinguish an address from data?
- Did I explain how the performance characteristic causes an effect rather than saying only “faster”?
- Did I apply embedded-system characteristics to the stated controller?
- Did I avoid detailed register transfers that OCR does not require?
Rewrite any statement that fails one of these checks.