Design of PWM Controller in a MCS-51 Compatible MCU

This paper presents a design of pulse-width modulated (PWM) controller module in a MCU based on MCS-51 structure. The design can generate 2-channel programmable periodic PWM signals. These output PWM signals from MCU can be used for a variety of applications including motor control. The function of the design allows users to select independent or complementary inversion timing relationships between 2 PWM wave forms. The latter mode selection also includes optional dead time function to support driving H-bridges and inverters. Therefore, users can control the output PWM signals through setting the duty-cycle registers. After the successful simulation at the front end, practical experiments made on a NIOS development board verify the design.