/ˈrɛdʒɪstər/
noun … “Small, fast storage inside a CPU.”
Register is a tiny, high-speed storage location within a CPU or microprocessor used to hold data, instructions, or addresses temporarily during processing. Registers allow the CPU to access and manipulate information much faster than using main memory, making them essential for instruction execution, arithmetic operations, and control flow.
Key characteristics of Register include:
- Speed: extremely fast compared to RAM or cache.
- Size: typically small, storing a few bytes or words, depending on CPU architecture.
- Types: general-purpose, special-purpose (e.g., program counter, stack pointer), and status registers.
- Temporary storage: holds operands, results, and addresses for immediate processing.
- Integral to instruction execution: works closely with the ALU and control unit.
Applications of Register include storing intermediate computation results, tracking program execution, passing parameters, and addressing memory locations efficiently.
Workflow example: Adding two values using registers:
R1 = 5
R2 = 7
R3 = ALU.add(R1, R2)
print(R3) -- 12
Here, the registers temporarily hold operands and store the result for further processing.
Conceptually, a Register is like a notepad on a worker’s desk: small, fast, and convenient for holding information that is actively being used.
See CPU, ALU, Memory, Microprocessor, Cache.