Mobile terminals such as mobile phones are adopting a dual core processor having MPU core and DSP core inside. Dual core processor significantly benefits mobile terminals in terms of performance and power consumption. However it makes the software development more complicated because both MPU and DSP requires its own development process. In order to improve the efficiency of software development with dual core processor, we propose a DSP scripting language and its execution environment that enables direct DSP programming from MPU side. This paper describes the design, implementation, and evaluation of the prototype system.