computer engineering Computer engineering (CoE or CpE) is a branch of electrical engineering and computer science that integrates several fields of computer science and electronic engineering required to develop computer hardware and software. Computer engineers n ...

, an execution unit (E-unit or EU) is a part of the

central processing unit A central processing unit (CPU), also called a central processor, main processor or just processor, is the electronic circuitry that executes instructions comprising a computer program. The CPU performs basic arithmetic, logic, controlling, a ...

(CPU) that performs the operations and calculations as instructed by the

computer program A computer program is a sequence or set of instructions in a programming language for a computer to Execution (computing), execute. Computer programs are one component of software, which also includes software documentation, documentation and oth ...

. It may have its own internal control sequence unit (not to be confused with the CPU's main

control unit The control unit (CU) is a component of a computer's central processing unit (CPU) that directs the operation of the processor. A CU typically uses a binary decoder to convert coded instructions into timing and control signals that direct the op ...

), some

register Register or registration may refer to: Arts entertainment, and media Music * Register (music), the relative "height" or range of a note, melody, part, instrument, etc. * ''Register'', a 2017 album by Travis Miller * Registration (organ), th ...

s, and other internal units such as an

arithmetic logic unit In computing, an arithmetic logic unit (ALU) is a combinational digital circuit that performs arithmetic and bitwise operations on integer binary numbers. This is in contrast to a floating-point unit (FPU), which operates on floating point num ...

(ALU),

address generation unit The address generation unit (AGU), sometimes also called address computation unit (ACU), is an execution unit inside central processing units (CPUs) that calculates addresses used by the CPU to access main memory. By having address calculations ...

(AGU),

floating-point unit In computing, floating-point arithmetic (FP) is arithmetic that represents real numbers approximately, using an integer with a fixed precision, called the significand, scaled by an integer exponent of a fixed base. For example, 12.345 can be ...

(FPU), load-store unit (LSU),

branch execution unit A branch, sometimes called a ramus in botany, is a woody structural member connected to the central trunk of a tree (or sometimes a shrub). Large branches are known as boughs and small branches are known as twigs. The term '' twig'' usuall ...

(BEU) or some smaller and more specific components."Execution Unit" discussion from the University of Massachusetts Amherst
archived on the

Wayback Machine The Wayback Machine is a digital archive of the World Wide Web founded by the Internet Archive, a nonprofit based in San Francisco, California. Created in 1996 and launched to the public in 2001, it allows the user to go "back in time" and see ...

It is common for modern CPUs to have multiple parallel functional units within its execution units, which is referred to as

superscalar A superscalar processor is a CPU that implements a form of parallelism called instruction-level parallelism within a single processor. In contrast to a scalar processor, which can execute at most one single instruction per clock cycle, a sup ...

design. The simplest arrangement is to use a single bus manager unit to manage the memory interface, and the others to perform calculations. Additionally, modern CPUs' execution units are usually pipelined.

References

Central processing unit Computer arithmetic {{Comp-eng-stub