This work applies a resolution reconfigurable ADC-assisted time-to-digital converter (TDC) to a two-step hierarchical TDC. The reconfigurable resolution and range are achieved by adjusting reference currents in time-to-voltage converter (TVC) and reference voltage in ADC. The proposed approach can be employed in a wide range of applications, while the hierarchical architecture allows the system to achieve high dynamic range. Measurement shows that the TDC achieves a resolution of 78ps with a 50MHz reference clock, or 39ps with a 100MHz clock. In both cases, the measurement rate is 384kS/s while consuming less than 6mW from a 3.3V supply.