The authors describe the architecture of a digital signal processor (DSP) well suited for motion video coding and its software development support tools. The DSP, named DISP (digital image signal processor), is image-coding oriented. It consists of several specified resources optimized for video signal processing, such as two-dimensional addressing and a combined arithmetic operation function. A simple and flexible video codec will be implemented with the DISP modules. The DISP software development support system, which consists of software support tools (assembler, linker and simulator) and a hardware support tool (hardware debugger), provides an interactive development environment. >