I want low frequency of pwm

Hi everybody,

    In my project,I would like to generate a pwm signal with an actual frequency of 50 Hz. I tried before, using the pwm_init() fuction, but the lowest frequency that i was able to reach was a frequency of 56.25 Hz.
    What should I do to obtain a frequency of 50Hz or lower?

Many thanks in advance.
My best regards.