Application-specific customisation of multi-threaded soft processors

A multi-threaded microprocessor with a customisable instruction set, CUStomisable Threaded ARchitecture (CUSTARD), is proposed. CUSTARD features include design space exploration and a compiler for automatic selection of custom instructions. Custom instructions, optimised for a specific application, accelerate frequently performed computations by implementing them as dedicated hardware. Field programmable gate array implementations of CUSTARD are evaluated using media and cryptography benchmarks, and commercial MicroBlaze processor is compared. As low as 28% area overhead for four interleaved threads and up to 355% speedup over a processor without custom instructions are demonstrated.