We are investigating an integrated design method for a device driver and a device in order to efficiently develop device drivers used in embedded systems. This paper evaluates whether SpecC, which is proposed as a system level description language, is applicable to integrated description language for the integrated design method. We use an SIO system to confirm the feasibility of using SpecC for integrating a device and description device driver. We manually convert the SpecC description to the device, the device driver and the interface in between and confirm that the conversion can be automated. We also confirm the feasibility of conversion when the partition point between the software and the hardware is changed. As a result, we show that SpecC could apply as a integrated design language of the design method.