computer science

Memory buffer register

Memory buffer register is a computer science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Memory buffer register rather than just read about it. In short: A memory buffer register (MBR) or memory data register (MDR) is the register in a computer's CPU that stores the data being transferred to and from the immediate access storage. It was first implemented in von Neumann model.

Key takeaways

Memory buffer register belongs to computer science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Memory buffer register to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Memory buffer register from memory before moving on to harder problems.

Reference excerpt

A memory buffer register (MBR) or memory data register (MDR) is the register in a computer's CPU that stores the data being transferred to and from the immediate access storage. It was first implemented in von Neumann model. It contains a copy of the value in the memory location specified by the memory address register. It acts as a buffer, allowing the processor and memory units to act independently without being affected by minor differences in operation. A data item will be copied to the MBR ready for use at the next clock cycle, when it can be either used by the processor for reading or writing, or stored in main memory after being written. This register holds the contents of the memory which are to be transferred from memory to other components or vice versa. A word to be stored must be transferred to the MBR, from where it goes to the specific memory location, and the arithmetic data to be processed in the ALU first goes to MBR and then to accumulator register, before being processed in the ALU. The MDR is a two-way register. When data is fetched from memory and placed into the MDR, it is written to go in one direction. When there is a write instruction, the data to be written is placed into the MDR from another CPU register, which then puts the data into memory. The memory data register is half of a minimal interface between a microprogram and computer storage; the other half is a memory address register (MAR). During the read/write phase, the Control Unit generates control signals that direct the memory controller to fetch or store data.

References

Worked examples

Example 1 — a first encounter with Memory buffer register

Start with the simplest possible case. Write down what Memory buffer register claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In computer science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Memory buffer register before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Memory buffer register ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Memory buffer register

In research: Memory buffer register appears in computer science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Memory buffer register in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Memory buffer register is common in secondary-school and first-year university syllabi. It links to neighbouring topics Computer hardware stubs, Digital registers, so understanding it makes those chapters shorter.
In everyday life: Look for Memory buffer register outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Memory buffer register in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Memory buffer register means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Memory buffer register out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Memory buffer register in simple terms?

Why does Memory buffer register matter?

Because it connects several computer science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Memory buffer register?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Memory buffer register.