Method, product, and system for integrating a hardware accelerator with an extensible processor

An approach includes the use of a description of instructions for invoking hardware accelerator and for a hardware accelerator to execute those instructions. In some embodiments, the instructions for invoking hardware accelerator and for a hardware accelerator to execute those instructions are described using a single language. These descriptions are then compiled into other languages for use in tool chains for generating simulators (a hardware and instruction set simulator and a hardware accelerator simulator). In some embodiments, the approach illustrated herein can be combined with state machine functionality to manage the execution of instructions that require multiple states. In some embodiments, the approach illustrated herein can be combined with an external register file for transferring information between a processor and a hardware accelerator.