Opportunities and obstacles in low-power system-level CAD

A case study in low-power system-level design is presented. We detail the design of a low-power embedded system, a touchscreen interface device for a personal computer. This device is designed to operate on excess power provided by unused RS232 communication lines. We focus on the design and measurement procedures used to reduce the power requirements of this system to less than 50 mW. Additionally, we highlight opportunities to use system-level design and analysis tools for low-power design and the obstacles that prevented using such tools in this design.