Hi,

Please let me know your application. It is highly doable in PBP-with mixed asm. In fact you can use darretl's routine of multipwm. You need another interrupt that is 3 times your base interrupt frequency and offset the main pwm value into the other. Still you will have offset errors (I suppose), since all the three PWMs are not updated at once. May be okay for driving a motor or UPS in general purpose application. Choice of the PIC is important as if you are playing with soft PWM then you might not have enough computing time left for other jobs.