This paper presents a novel test pattern generation flow to detect stuck-at and transition faults simultaneously. Both fault models are transformed into a unified fault model for a proposed 2-time-frame circuit model. This makes it possible to generate patterns for both types of faults in one ATPG run with no need to modify the ATPG tool. A highly compact pattern set can thus be obtained which requires less test data volume and shorter test application time without degrading the fault coverage for either type of faults. Experimental results show that, compared to the conventional methods, the proposed method can reduce the total test pattern counts by up to 12.27% and 15.54% and test application times up to 12.06% and 15.58% for ISCAS'89 and ITC'99 circuits, respectively.