et. al, S. K. G. K. P. “IMPLEMENTING AND MODELLING PWM CONTROL AND ITS DUTY-PHASE CHANGES USING VERILOG”. International Journal of Advanced Science and Technology, Vol. 29, no. 2, Jan. 2020, pp. 2370 -78, https://sersc.org/journals/index.php/IJAST/article/view/3659.