Two novel low complexity dual-mode pulse generator designs suitable for FFs with triggering mode control are presented. The proposed designs successfully integrate XOR/OR (AND/XNOR) functions into a unified pass transistor logic (PTL) module to provide control on single- or double-edge operations. The designs use as few as 8 transistors each and ingeniously avoid the signal degradation problem inherent in most PTL circuits. As the only dual-mode designs so far, the proposed designs also outperform rival single-mode designs in both aspects of circuit complexity and power consumption.