One of the controller from the Philips' 80C52 family, the 80C552, comes with two PWMs and ADC. I had used the controller in a number of servo drive projects. I also used the Intel's 16-bit 80196KC before which has three PWMs and ADC for a 3-phase brushless motor controller project. However, the Intel's part is a bit complicated to used. All these PWMs are using comparator/counter to generate the pwm signal and will generate the same pulse width after a value is written into the pwm port. Not software is requred to maintain the signal until a new pulse width is required.