Unlike static CMOS circuits, the standby energy in sense amplifier-based pass transistor logic (SAPTL) circuits can be decoupled from its performance, allowing separate optimization strategies for leakage and speed. In this paper, a 64-byte parallel cyclic-redundancy check (CRC) generator is designed and implemented using asynchronous 90nm SAPTL circuits, with a simulated minimum energy point that is 25% lower than the equivalent complementary static CMOS implementation. The low leakage operation results in (a) an 7.9X reduction in measured energy when V_DD is reduced from 1V to 0.3V at α = 0.1 and (b) a 10% reduction in measured delay with a stack forward body bias of 0.4V, with no corresponding increase in energy.