CPU registers

The microprocessor chip serves as the central processing unit (CPU). It contains a clock that regulates the flow of data and instructions (each instruction takes a certain number of clock cycles to execute).

There is also an index register that keeps track of the instruction being executed. A small number of locations called registers within the CPU allow for storing or retrieving the data being used by instructions much more quickly than retrieval from main memory (RAM).

CPU registers is an important microarchitectural component used for storing operands and results of instructions. The design and operation of CPU registers has crucial impact on the performance, energy efficiency and reliability of the processor and hence, several techniques have been recently proposed to manage RF in modern processors.

The register file is an integral part of the CPU and as such is clearly defined in the architecture. The register can provide operands directly to the ALU (arithmetic logic unit).

Memory reference instructions load or stored data to/from the registers contained in the register files. The register file of the CPU holds the values for GPRs (General-purpose registers) and floating-point registers (FPRs). Additional registers for CPU control and addressing information are generally provided.

Typically, the instruction register advances to the next instruction. The instruction is fetched, decoded and sent to the CPU’s ALU for processing.
CPU registers