Nonprocessor

Nonprocessor is a nonstandard term used in computing to describe components that do not perform general-purpose computation. It is used to contrast with processors such as CPUs or other programmable cores, to indicate elements that provide support, memory, or dedicated tasks without executing arbitrary instructions.

In hardware architectures, nonprocessor components include memory (RAM, ROM, cache), non-volatile storage (SSD, HDD), and memory controllers; I/O controllers and bridges; and peripheral devices that do not themselves run code. Some system-on-chip designs categorize memory subsystems, DMA engines, bus controllers, and other fixed-function units as nonprocessor blocks, integrated with processing cores.

In software or firmware contexts, "nonprocessor" may refer to data or subsystems handled by hardware peripherals or by the system's I/O subsystems, or to resources that are not executed as software code on the main CPU.

The term is informal and context-dependent, and is not widely standardized. Its meaning varies by author and discipline, so readers should rely on the surrounding explanation to determine what is meant by nonprocessor. See also peripheral, chipset, memory subsystem, and input/output controller for related concepts.