SystemC

SystemC is a set of C++ classes and macros that provide an event-driven simulation environment for system-level modeling of hardware and software. It is not a separate language; rather, it is a library that extends C++ with hardware-oriented constructs used to describe concurrent behavior, timing, and communication. SystemC is widely used for architectural exploration, virtual prototypes, and hardware/software co-design.

Key features include a discrete-event simulation kernel, time modeling with sc_time and sc_clock, and the concept of delta cycles. Design units are expressed as modules (SC_MODULE) containing processes (SC_METHOD, SC_THREAD), with ports, signals, and interfaces. Communication uses signals and transaction interfaces, most notably the Transaction-Level Modeling (TLM) library for abstract communication between components.

SystemC is standardized by IEEE as 1666. The ecosystem includes multiple simulators and toolchains, both open-source and commercial. The TLM-2.0 library provides a standardized way to model communication at a high level, enabling fast virtual prototyping and software development alongside hardware models.

Origins and usage: SystemC originated with the Open SystemC Initiative (OSCI) in the late 1990s and was later standardized by IEEE. It is used for system-level design, architecture exploration, IP development, and hardware/software co-design, allowing early software development and high-level modeling before RTL implementation.