TDA4AEN-Q1: What's the time unit for cycle count from FFT Lib performance?

Hi Gibbs,

The "cycle count" in TI FFTLIB performance documentation refers to the number of CPU clock cycles, not nanoseconds. The cycle count measures how many clock cycles the C7x DSP core takes to execute the FFT operation.

For performance measurement, we typically use the __TSC counter. 

To know more about TSC(Time Stamp Counter) please refer : https://software-dl.ti.com/codegen/docs/c7000/optimization_guide/3_profiling/compopt-prof_clock_function.html?

To convert cycle count to actual execution time:

Time (ns) = Cycle Count / CPU_Frequency(MHZ) × 1000

Adding FFTlib FAQ link for your reference: https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1555358/faq-tda4vh-q1-how-to-use-fftlib

Regards,

Betsy Varughese