Pin count-aware biochemical application compilation for mVLSI biochips

Microfluidic biochips are replacing the conventional biochemical analyzers and are able to integrate the necessary functions for biochemical analysis on-chip. In this paper we are interested in flow-based biochips, in which the fluidic flow manipulated using integrated microvalves, which are controlled from external pressure sources, connected to “control pins”. By combining several microvalves, more complex units, such as micropumps, switches, mixers, and multiplexers, can be built. The current practice is to design these biochips by hand in drawing tools such as AutoCAD, and to program them manually by individually controlling each valve. Recent research has proposed top-down physical synthesis Computer- Aided Design tools, and programming languages and compilation techniques to automatically derive the control signals for the valve actuations. However, researchers have so far assumed that the number of ports used to drive the valves (control pins) is unlimited, which has resulted in very expensive, bulky and energy consuming off-chip control and infeasible control routes in the biochip control layer. In this paper, we propose a methodology to reduce the number of control pins required to run a biochemical application. We focus on the compilation task, where the strategy is to delay operations, without missing their deadlines, such that the sharing of control signals is maximized. The evaluation shows a significant reduction in the number of control pins required.