Testable Design of Template based QDI Asynchronous Circuits

Complexity of design and testing are the major obstacle for widespread use of asynchronous circuit in digital circuit design. Template based synthesis of asynchronous circuit is accepted as an effective way to decrease complexity of design of asynchronous circuit. One of the popular pre-designed templates that most synthesis tools use it to synthesis QDI asynchronous circuit is Pre-Charged Full Buffers (PCFB). In this paper we study the effect of single stuck-at fault in PCFB templates and categorize fault effects, then for each category introduce a circuit that detect faults. Experimental results show that using these additional circuits in PCFB buffers can improve the testability from 68.55 percent to 90.32 percent.