Register is a noun, meaning an official document of various useful data, such as the list of past events, transactions or names that a bank keeps. It can also be a verb, meaning to mark or record something officially, such as registering your car at the DMV or registering for classes at the beginning of a semester. Lastly, it can be a piece of electronic equipment such as the cash register that you use to process sales and payments.
In computer architecture, registers act as the brain’s immediate memory that the CPU uses to perform operations. They’re small, high-speed storage units that are located within the processor and ensure rapid access to important information, enhancing overall performance. This article dives deep into the role of registers in the CPU, how they work and how they differ from other types of memory such as memory buffers.
A register is an active data storage area that can be accessed by the processor at any time. There are many different varieties of registers that can be found in ICs. They can be called status registers, control registers or data registers. The name is simply a convenient way to explain the function of these specialized data storage areas. Generally, the specific register settings are very carefully explained in the data sheet for each IC type.
The CPU needs to be able to quickly and efficiently retrieve the most important information at any given point in time. To achieve this, the most common solution is to store temporary values close to the CPU, in registers. This optimizes the workflow by reducing the amount of times the CPU has to access slower, external memory locations to obtain the necessary information.
Registers can be general or special purpose, and they can be read and written to at the same time. This makes them flexible tools in the CPU, as they can store data that is needed for a variety of different operations, such as multiplication or addition. They can also hold the results of these operations, thereby minimizing the number of times the CPU has to go out to memory to get the information it needs.
One important aspect of a register is that it has a high speed operation and requires minimal power. This is because most of the operations performed on it take place locally to the processor, and they’re done without moving any bits outside of the register. This makes the register a very efficient form of memory, which is why it’s used so frequently in modern computer architectures.
The register is also often pitch-matched to the datapath, meaning that it’s designed to operate with the same bit pitch as the most important unit in that area of the CPU. This helps to conserve space by avoiding the need for multiple register files that would otherwise be required on machines with wider datapaths, such as those with more than three instruction busses. It is possible to save more space on some systems, however, by incorporating multiple copies of the register file into the CPU’s decoder or pipeline.